Of all the Yoga books that I’ve read and collected over the years if I had to choose just one, it would be Light on Yoga, by B.K.S. Iyengar.

Light on Yoga is really an all-encompassing Yoga guide to attaining physical, mental and spiritual well-being. Light on Yoga is divided into 3 parts.

Part 1 is a succinct and thorough explanation of what Yoga is and traces Yoga’s historical origin to ancient India.

Part 2 covers yogasanas, bandhas, and kriyas and is an encyclopedic-like in nature with hundreds of asanas, each with a photograph. Each asana has step-by-step instructions to help perfect the asana. The benefits of asana, the ailments it cures, as well as the precautions it requires are also included.

Part 3 of the book is dedicated to Pranayama, an array of yogic breathing exercises and techniques.

The book concludes with two appendices. The first appendix lays out weekly plans to build your own practice, for 3 different levels, from beginner to advanced. The second appendix recommends specific asanas for targeting and curing specific diseases. Light on Yoga concludes with an extensive glossary.
Light On Yoga was first published in 1966. It is considered to be a must-have for serious practitioners of Yoga.