From Amazon.com:

This fully illustrated book is the most complete text available on the theory and practice of Kriya Yoga. The Spiritual Science of Kriya Yoga takes the student step-by-step through the eight stages of Patanjali's Kriya Yoga system and contains extensive chapters on hatha yoga pranayama, mantra, meditation and samadhi. Goswami Kriyananda explicitly teaches how specific asanas can be used to balance each of the seven chakras. If you could only have one book on yoga, this would be it!

From the Author

It is my sincere hope that you find this book meaningful in balancing your life and developing greater discipline, wisdom, and spiritual maturity. For over 40 years, the essence of my teaching has been the simple truth that the earth life and the spiritual life are one -- your life. I offer these teachings that you might find the bridge of wisdom that unites your inner and outer worlds.

You are the creative principle. Only you, for yourself, can take those teachings and make them your own, bringing you to the realization of your fullest potential. It is my continual meditation that your life be filled with ever greater wisdom, love, light, and laughter.

Goswami Kriyananda