The Practice of the Presence of God, by Br. Lawrence of the Resurrection.
The Imitation of Christ, Thomas a Kempis.
The works of St. Teresa of Jesus (begin with The Way of Perfection) and of St. John of the Cross (begin with either The Spiritual Canticle or Living Flame of Love).
Introduction to the Devout Life, St. Francis De Sales
Autobiography of St. Therese of Lisieux (Story of a Soul)
DISCLAIMER: Catholic Answers has turned over the archive to Catholic-Questions.org and no longer owns, manages, or moderates the forums. For additional apologetics resources please visit www.catholic.com.