RECOMMENDED BOOKS
The Heart of Yoga by T.K.V. Desikachar
Goes into great detail about the fundamentals of developing a personal practice.
Yoga Toolbox by Joseph and Lillian Le Page
Highly recommended for Yoga Teachers. Goes into the depths of the Asana (posture) aspect of Yoga.
The Seven Spiritual Laws of Yoga by Deepak Chopra
Yoga Philosophy viewpoint.