Classical Hatha Yoga 

Recommended Books

1. The Book of Yoga: The Complete Step-by-Step Guide, The Sivananda Yoga Centre, Written by Lucy Lidell with Narayani and Giris Rabinovitch, Photography by Fausto Dorelli, Ebury Press, London, 1983.
The best asana manual. Excellent illustrations. Weak on kryas.

2. Learn Yoga in a Weekend, The Sivananda Yoga Vedanta Centre, Alfred Knopf, New York, 1993.
An excellent compact book!

3. A Systematic Course in the Ancient Tantric Techniques of Yoga and Kriya, by Swami Satyananda Saraswati, The Bihar School of Yoga, K.L. Bhargava & Co. Impression House, Bombay, 1981.
A veritable encyclopedia of Yoga. Contains in-depth description of asanas, pranayamas, kryas, mudras, and related information, as for example, an excellent article on vegetarianism and Yoga.