The Mindful Way Through Depression by Mark Williams, John Teasdale, Zindel Segal, and Jon Kabat-Zinn - a book version of the authors' eight-week program, Mindfulness Based Cognitive Therapy for Depression.
The Happiness Trap (amazon link here) by Russ Harris - An accessible, well written guide for working with a variety of problems of the mind using techniques from Acceptance and Commitment Therapy. Highly Recommended!
My Grandfather's Blessings by Rachel Naomi Remen - A book of short essays that amount to a very succinct emotional education for anyone who is suffering with a lack of meaning or internal struggle.
Life After Trauma: A Workbook for Healing by Dena Rosenbloom, Mary Beth Williams and Barbara E. Watkins.
What Really Helps by Karen Wegela - a guide to being more present to yourself and others in your life, written by a professor of Naropa University's Contemplative Psychotherapy program. Covers many of the ideas of Contemplative Psychotherapy in an easy to digest, practical format.