There are several books that I highly recommend to clients depending on the issues that they are addressing. They include:
The Emotion Code by Dr. Bradley Nelson
Singing Magnets are an accompanying tool for The Emotion Code.
Love Is Letting Go Of Fear by Gerold G. Jampolsky, M.D.
The Jeshua Letters: A Journey of Awakening by Marc Hammer
The Way of The Servant: Living The Light of Christ by Jon Marc Hammer