The following selection of yoga books and others are all ones that I either use regularly to help me plan classes for my students, or that I have enjoyed very much. I hope that you will enjoy some of them too!

Asana Pranayama Mudra Bandha

Swami Satyananda Saraswati

A very useful yoga book which contains many postures (asanas), including the Pawanmuktasana series and some other variations not in Iyengar's book.

The Yoga Bible

Christina Brown

Very clear and easy to read - suitable for all levels. 

Light on Yoga

BKS Iyengar

Classic book with detailed instructions on a large number of postures. Also has sections on pranayama, suggested courses for beginners, intermediate and advanced students, as well as suggested asanas and other practices for various diseases.

The New Book of Yoga

Sivananda Yoga Centre

A good introduction to yoga which covers postures, breathing, diet, meditation, and some philosophy/background.

Yogaflows

Mohini Chatlani

Focuses on sequences of yoga postures, and shows linking moves between the selected asanas.

Instructing Hatha Yoga

Kathy Lee Kappmeier and Diane M Ambrosini

Useful for (aspiring) teachers; very detailed information. Includes a DVD.

Yoga Posture Adjustments and Assisting

Stephanie Pappas

Useful for (aspiring) teachers – clear pictures and text

Yoga Mind, Body and Spirit

Donna Farhi

Very thorough – with modifications, prenatal suggestions, variations for beginners and advanced students etc.

Healing Mantras

Thomas Ashley-Farrand

Contains a large number of interesting mantras with background information about each one. Includes a CD

Acu-Yoga

Michael Reed Gach

Marries yoga with acupuncture – shows which meridians/nadis are being worked on etc. Includes yoga postures for various health problems, and shows the acupuncture points affected by the poses.

Autobiography of a Yogi

Paramahansa Yogananda

Spiritual autobiography - a classic.

Initiation

Elisabeth Haich

Spiritual autobiography/reincarnation, some of it set in ancient Egypt, and some in the 20th century.

The Chasm of Fire

Irina Tweedie

Spiritual autobiography, in the Sufi tradition.

The Power of Now

Eckhart Tolle

Difficult to define, except it aims to take/keep you in present moment awareness, and is very inspiring.

Loving What Is

Byron Katie

Focuses on using a set of questions to show how we misunderstand reality and thereby make ourselves unhappy because of what we believe to be true; by answering the questions honestly we are led to a joyful state.

Surprised by Grace

Amber Terrell

Spiritual autobiography – Amber is a student of the American guru Gangaji, who is herself a student/disciple of an Indian guru, Papaji/Poonja (now dead).

Yoga Wisdom and Practice

B K S Iyengar

A recent offering from one of the top names in yoga: beautiful pictures, with the emphasis firmly on wisdom, but including some interesting comments on practice also.