There are some classic books on the practice of pranayama, the theory and philosophy of the subtle, vital pranic force and Swami Satchidananda’s “Breath of Life” CD that includes a guided pranic healing visualization.
1. Breath of Life CD: Integral Yoga Pranayama taught by Swami Satchidananda
2. The Yoga of Breath & Sense Control (DVD) by Swami Satchidananda (also available as a downloadable MP3)
3. Science of Breath by Swami Rama, Rudolph Ballentine MD and Alan Hymes
4. Science of Breath by Yogi Ramacharaka
5. The Yoga of Breath: A Step-by-Step Guide to Pranayama by Richard Rosen
6. Light on Pranayama by BKS Iyengar