These are some of the precious books I've collected so far that are concerned with Mysticism or spirituality in some way.  If you have any titles that you think I should add, please contact me.

Nearer to the Heart of God -- edited by Bernard Bangley (Paraclete Press 2005)

Daily devotional of uplifting spiritual insights compiled from works of various mystics throughout the ages. This would be a perfect start for those wanting to easily learn more about the mystic worldview, as it's edited to highlight basic ideas and they're presented in very readable format.

The Practice of the Presence of God -- by Brother Lawrence (Whitaker House 1982)

A small “instruction manual” outlining the very fundamental thought of those whose essential focus is to dwell in union with the Creator. These are excerpts from letters and conversations of one who lived this practice continually. Can be read in one sitting, and is small enough to be carried around in a pocket or purse.  Christianbooks also carries other editions of this title.

Dialogue of St. Catherine of Siena -- translated by Algar Thorold (Tan 1974)

Treatises from the 14th century mystic who dictated her conversations with God to her secretaries as the visitations were taking place. Insightful, but the language is a bit archaic and challenging to read; as you go along you pick up the drift of it and the reading gets easier.

The Wisdom of the Christian Mystics -- by Timothy Freke (Godsfield Press 1998)

From the Wisdom of the World series, this is a short introduction to the mystics of history and their contribution to the teaching of the importance of turning toward God. Illustrated.

The Mystical Doctrine of St. John of the Cross -- Abridged and introduced by R.H. J. Steuart, S.J. (Sheed and Ward 1937)

Selections from the work of St. John, put together in such a way as his tenets, normally confusing in content and repetition, can be better understood. St. John is looked upon as the definitive teacher of the mystic path, putting the methods of this profession in an educational form.

 
The Life of St. Teresa of Avila by Herself -- translated and introduced by J. M. Cohen (Penguin Books 1957)

From the Penguin Classics series. St. Teresa of Avila, a sixteenth century contemplative who, beside being on the receiving end of clear and documented mystical experiences, was a contemporary of St. John of the Cross, wrote extensively about contemplative prayer, and established Carmelite houses. There are many different editions of this book.

 
Divine Guidance: Seeking to Find and Follow the Will of God
by Susan Mutt and Adrian Van Kaman

This is more of a self-help book with the goal of getting a person to figure out how to know if they're following what God wants. The book uses the Sermon on the Mount and the Beatitudes to teach this lesson. They expand on the 12 steps used in these parts of Scripture as practical guidelines to divine guidance.

Self-Abandonment to Divine Providence
by Father J. P. De Caussade, S.J. (1675-1751) by Algar Thorold

This work follows the Carmelite tradition of St. John of the Cross and St. Teresa of Avila, and also the tradition of St. Francis de Sales. There are two parts: the virtue of self-abandonment and the state of self-abandonment. Self-abandonment isn't just the acceptance of the will of God, which is the duty of every Christian -- it's the real affective gift to God of all the powers of the soul. "If we knew how to leave God's divine hand free to act we should obtain the most eminent perfection -- all would obtain it for it is offered to all." De Caussade emphasizes that the things that happen when we give our self-will --abandon our self-will -- and throw the soul open to the divine action are present in every event in life and that no single external circumstance is more than a temporary instrument of God's action which shows us God's will here and now.

Guidelines for Mystical Prayer
by Ruth Burrows (Dimension Books, Denville, NJ 1976)

Written by a contemplative nun, this book contains some hard-to-hear realities. It’s an explanation of contemplative paths without the slavish devotion to church which bothers me in my St. Teresa of Avila studies.

 
How to Understand God
by Dominque Morin (Crossroads, New York 1990)

A philosophical look at the belief in God, but in a contemporary and upbeat jargon that only occasionally lapses into philosophical babble. Although pro-God, the author tries to keep an open mind to other beliefs, especially the ones brought on by scientific technology. Delves into “proofs” and common wisdom to show how a person comes to one belief over another.

 
Speaking to God
collected by Nancy Benvenga (Ave Maria Press, Notre Dame, Indiana 1993)

Prayers organized and titled, so that you can pick out one by it’s naming. Some traditionalist and some contemporary.

Spirituality and Mysticism
by James A. Wiseman (Orbis 2006)

A part of the “Theology in Global Perspective Series”, this offering is heavy on philosophy, but the kind that is cloaked in simple language. It traces the history of Mysticism throughout the world, giving a global perspective on the subject and treating true Mysticism seriously. Though educational, the one thing I found disturbing in parts of the book is the common mistake of treating Mysticism as a political statement by those calling themselves mystics who have a worldly agenda such as feminism and anti-war sentiment. While such people can have mystic experience, the kind of Mysticism I'm interested in is the kind that focuses on the ethereal and eternal, not the worldly and temporal. Also, the book seems to “rate” spirituality by the economic condition of its practitioners – to me, while poverty helps one to draw close to God, it doesn't follow that first-world Mysticism is bogus.

 
On Union with God 
by Albert the Great (Continuum 2000)

This is from the “Ways of Mysticism Series” -- nicely bound and illustrated. Albertus Magnus was a twelfth century Doctor of the Church who had an extremely clear vision of the simplicity of Divine Union. This treatise is one of those that I consider a “handbook of Mysticism”; one that you want to carry around with you to remind you of why you feel as you do. This is also good for beginners and those who just want to look into the subject – the entries are short and to the point. Seekers will often find themselves and their innermost thoughts highlighted in these pages.

The Cloud of Unknowing 
Edited by Evelyn Underhill (Dover 2003)

This work by an unknown medieval writer needs to be translated further than this edition was in order to be completely palatable by even experienced students of Mysticism. There are many other editions of this work that you may understand and like better. But I do like to read things in the original medieval flavor because if you broaden your mind as you read, you will automatically get through the rough spots and the important points will jump out at you. Have your highlighter ready so you can go back again and find the points you need. The book has crucial things to say about reality, finding the vision, and acting on it. It involves the reader in the art of abandoning all thought in order to find divine love.

The Collected Works of St. Teresa of Avila, volume two
Translated by Kiernan Kavanaugh and Otilio Rodriguez (ICS Publications 1980)

Includes The Way of Perfection, Meditations on the Song of Songs, and The Interior Castle. Woman especially would enjoy the way Teresa writes – plainly and humbly, while between the lines you know she's just barely putting up with the inferiority to men she must live with as both a woman and a religious. But humility is a good part of Mysticism and Teresa practices it well. Yet as a teacher she's unparalleled, because she writes as a confidant would – someone who knows your fears, has experienced them too, and has gotten past it. There is something here for every student of Mysticism, even the treatise on how to act as a good nun. And of course the book contains her definitive treatment of the subject of contemplative prayer.

Conversations with God, Book 1 by Neale Donald Walsch (G. P. Putnam's Sons – New York)

I picked this out because, what could be more up my alley? After the first few pages I realized that because conversation with God is up my alley, I was very disappointed in this book. But I held out through the end, and even though I didn't change my mind overall, I did see that there were many moments when God was not made to sound like a dysfunctional idiot and the theory at hand was, in my opinion, right on. I will be the first to acknowledge that though God never talks to me this way, he might easily provide such insight to Mr. Walsch. But I'm fairly certain that the author just took his own beliefs and tacked God's personification onto them. Or perhaps he has fallen for something I myself am prey to – taking legitimate insights from God and expanding on them to the point that they are just manifestations of one's own reflection. For someone who can discern, this can be overcome and many points in the book are worthy of study and reflection. But many who cannot discern will read this book, and I think in this way the book does God an injustice. Books 2 and 3? No, thanks.

Praying with Thomas Aquinas, by Mary Mercy Houle, Michael Monshau, and Patrick F. Norris (St. Mary's Press;Christian Brothers Publications, Winona, Minnesota)

From the “Companions for the Journey” series, this treatment shares Aquinas with the mystics who would best appreciate him, although the authors are too shy to focus on him as a mystic himself. This book would be a handy interpretation of his works for those of us who find Summa Theologiae too difficult. Thomas had a beautifully basic spiritual relationship with God that we would like to imitate, and a reasoned approach to how this can be accomplished. The book outlines this approach nicely and takes us through Thomas' beliefs by encouraging exercises to discover our own spiritual style.

The Silent Cry – Mysticism and Resistance

by Dorothee Soelle (Fortress Press, Minneapolis)

There is a lot here to be learned about the process and practice of Mysticism, but the book degenerates into just another case of an author using Mysticism for their own preformed agenda. In this case, it's the leftist utopia model that has never worked anywhere it's been tried. Yes, Mysticism is all about egolessness, possessionlessness, and non-violence, but the goal is a relationship with God; not political activism. Yes, consumerism is rampant and its effects are persuasive, but radicalism never solves immorality, and it irritates the very people who could agree with you and make a real difference through studied moderation.
 

The Words of Jesus Christ

(Blue Heron Books, Vancouver)

 
This is my favorite source for Lectio Divina. It takes just the bare essentials of the New Testament works of Jesus, and uses them to background His actual words. So what you have is a compact King James Version of the gospels in a title in the Book Blocks series.

Experiencing Union with God Through Inner Prayer & The Way and Results of Union with God

by Madame Jeanne Guyon (Bridge-Logos Publishers, Gainesville, FL)

Two books in one volume outline perfectly the practice of devotional mysticism. Extensively revised into modern English, the short and simple chapters explain the method of inward prayer and what can be expected on the way to perfection. Of all the mystics, Madame Jeanne Guyon's life is probably one of the most interesting. She was persecuted because of her mysticism, but never wavered from what she knew was right.

Introduction to a Devout Life

by St. Francis de Sales (Frederick Pustet and Company, Ratisbon, Rome, New York, Cincinnati)

The well-known book which defines for religious and lay persons alike the ideals of a Christian life as written by this bishop of Geneva who lived in the late 16th century to the early 17th century. To us now much of this writing seems quaint, naive, and at times scientifically incorrect, but the essence of it still applies – that obedience, humility and purity are pleasing to God.

The Way of Mysticism

arranged by Joseph James (Jonathan Cape, London, 1950)

Mystic quotes of seekers from Abbas Effendi to Sir Francis Younghusband; divided into two parts – God Turns Towards Man, and Man Turns Towards God, with the focus on the still small voice crying out in the divided world of today.

The Soul Afire -- Revelations of the Mystics

edited by H. A. Reinhold (Pantheon Books, 1944)

Meant to showcase the beauty and loftiness of the path to perfection that is Mysticism through writings of those who have experienced it from antiquity to the present. This book takes the main tenets of mystical life, such as detachment and silence, as headings and inserts writings pertinent to each particular treatment. Much of the influence is Christian, and there is an entire section devoted to the mystical apprehension of Jesus.

The Mystical Life

by Pascal P. Parente (B. Herder Book Company, St. Louis and London, 1946)

This is a textbook on the role of Mysticism as the link between the faith of this world and the glory of the next. It covers the mystical elements, states, and phenomena. It also provides an extensive bibliography.

My Utmost for His Highest

by Oswald Chambers (Barbour and Company, Inc., Westwood, NJ, copyright 1935)

Though not mystical by any stretch of the imagination, Chambers makes the case for mysticism without meaning to. This daily devotional is a well-known Christian work that concentrates on the redemption as the way to God, but contains methods of thought that are not far removed from mysticism. For just as we think we've reached the point where we can be smug about our dedication to God, there appears between the lines the admonition against premature pride in our spirituality. We can always do better, or as the mystics say, the path to perfection is a holy state which we don't count on fully finishing in this world.

Out of the Quiet

by Peter Wallace (Navpress, Colorado Springs, CO, 2004)

A bible-based study on the invitation of God for you to come closer, live abundantly, and reach out. A nice mix of biblical references, meditation, and personal witness, it's a treatise on the desirability and possibility of a personal relationship with God.

The Deeper Life, An Introduction to Christian Mysticism

by Louis Dupre (Crossroad, New York, 1981)

Nine lectures given to monks at a Kentucky abbey, concerning our innate desire for the knowledge of God despite our limitations. Describes the stages of Mysticism paralleled with the various mystic principles that power them.

Door Through Darkness

by Sister Eileen Lyddon (New City Press, Hyde Park, NY)

This would be a great book for those who want to have a better understanding of the work of St. John of the Cross. First it gives some biographical background and the overall basic tenet of St. John's mysticism. Then it breaks down the four “nights” and explains and expands on each one. The book closes with a general review of the principle of a unitive relationship with God, and what we do with it in our daily lives.

The Best of Fenelon

revised and updated by Harold J. Chadwick (Bridge-Logos Publishers, Gainesville, FL)

Part of the Pure Gold Classic series, this volume contains three of Fenelon's best works – Spiritual Letters, Christian Counsel, and Maxims of the Saints. Fenelon is my favorite mystic author because he pulls no punches. For all the misery he was put through because of his beliefs, he remained staunchly loyal to the word of God personally experienced. The second section of this book outlines the story of his run-in with the powers-that-be and makes great reading for those who believe as he does and feel persecuted for it.

The Only Necessary Thing

by Henri J. M. Nouwen; edited by Wendy Wilson Greer (The Crossroad Publishing Company, New York, NY)

These excerpts from other volumes are a treatise on the many aspects of living a prayerful life. Compiled under headings such as “Listening”, “Community”, and “Hindrances”, each chapter follows a theme and pulls Nouwen's thoughts from his many works into a cohesive tool. Nouwen was a man of great insight and experience, but his humility always shows through to the point that we never feel he is “above” us. We consider his words as advice from a friend.

By Way of the Desert

compiled and modernized by Bernard Bangley (Paraclete Press, Brewster, MA)

An inspiration a day based on the history of the various ammas, abbas, monks, nuns, and solitaries who went to the desert to seek God quietly. The desert was thought to be the place for clarity, where God would ensure out of the severe conditions a new and vivid direction. Stripped of externals, the devouts who had confined themselves to their cells saw the essentials more clearly. Though this way of thinking often seems foreign to us, it does open up a whole new thought each day to ponder.

Thomas Aquinas, Spiritual Master

by Robert Barron (Crossroad Publishing Company, New York 1996)

Here is a great introduction to the Classical Theologian – as always, made accessible to today's reader through the Spiritual Legacy series. Notoriously dry to read, the works of Thomas Aquinas nevertheless have much to say to anyone willing to learn. His theology reflects his certainty in the love and goodness of God, and his style of statement, objection, and refutation in the Summa Theologica anticipates the arguments against his philosophy and meets them with studied response. This book outlines those theological tenets briefly, and in doing so introduces Thomas Aquinas to those who may never feel qualified to pick apart the originals.

Divine Love Came Down!

edited by Nancy Sabbag (The Word Among Us Press, 2003)

This book contains articles from various works of Saint Alphonsus Liguori. A short work, easy reading; this would be one to read from cover to cover and come away with a concise history of the God's salvation plan and how we live it out in our daily lives. Short passages are also good for random inspirational reading.

 Waiting for Review:

The Imitation of Christ

Mysticism 

Saint Ignatius of Loyola - Personal Writings

Everyday Grace

Christian Perfection and Contemplation

A Course in Miracles

The Prayer of Jabez

My Way of Life 

Pseudo-Macarius: The 50 Spiritual Homilies and The Great Letter 

Wonderful and Dark is This Road

The Joy of Full Surrender

Grace for the Moment -- Morning and Evening Edition