I always say that when you look for a book on a particular topic, just go to your library or a bookshop and see which book speaks to you. But: As you asked, here are some suggestions for books on yoga.
On the history of yoga
Yoga Body: The Origins of Modern Posture Practice by Mark Singleton
Academic yet still digestible. Drawing on a wealth of research on ancient yoga texts, this book explains how yoga has developed throughout time, dispels many myths about the practice, and shows how yoga has taken on a life of it's own in different parts of the world.
On yoga poses
Hatha Yoga Illustrated by Martin L Kirk and Brooke Boon This is the very first yoga book I bought. It's quite old and well-thumbed now but I still refer to it. 77 common poses are presented comprehensively, with beautiful photographs, concise instructions, variations, and a selection of yoga sequences. All you need to look up basic information about a pose.
On teaching yoga
The Heart of Yoga: Developing a Personal Practice by T.K.V. Desikachar This book has greatly influenced me as a teacher and shaped my approach to teach a personalised, permissive style of yoga. It covers a wide range of topics from postures to conscious breathing, meditation, and philosophy. Highly commended even if you are not a yoga teacher.
On 'your kind of' yoga
Awakening the Spine: Yoga for Health, Vitality and Energy by Vanda Scaravelli Again, this book has hugely influenced me. It is not a 'how to' manual but a very personal exploration of the practice of yoga by by a leading female yoga teacher. It is an amazing book for those who look for inspiration and those who want to deepen their awareness of themselves.
On Yin Yoga
Insight Yoga: An Innovative Synthesis of Traditional Yoga, Meditation, and Eastern Approaches to Healing and Well-Being by Sarah Powers If you are interested in an introduction to the Chinese meridian system and how it relates to Yin Yoga, this book will give you a good overview. Its well-structured and offers many opportunities to reflect on how you practice yoga (Yin or not).
On yoga and life
Light on Life: The Yoga Journey to Wholeness, Inner Peace, and Ultimate Freedom by B.K.S. Iyengar Iyengar was arguably the most influential yoga teacher ever in bringing yoga to the West. His book Light on Yoga has become THE reference for yoga poses, while Light on Life explores the philosophical and spiritual aspects of yoga. It's a never ending source of food for thought.
Off the beaten track
The Radiance Sutras: 112 Gateways to the Yoga of Wonder and Delight by Lorin Roche Ok, this is a perhaps rather specialist text written at about 850 CE, but I love it because its language and spirit are simply beautiful. I read from it often in my Yin classes. It is at once a love song to life and an encyclopedia of 112 tantric teachings, along with guidance in how to embody and practice them.
On anatomy and physiology
The physiology of Yoga by Andrew McGonigle and Matthew Huy I've attended a few CPD courses with Andrew McGonigle and love his down-to-earth and science-based approach to yoga. This book is written in a clear and concise manner, providing evidence for the benefits of yoga for your body and health, while busting many far-fetched myth you may have come across.
On meditation
The Miracle of Mindfulness: An Introduction to the Practice of Meditation by Thitch Nhat Hanh This is a classic by famous Zen master Thitch Nhat Hanh, bringing mindfulness and meditation to everyday activities. If you are interested in mindful meditation also look out for books by Jon Kabat-Zinn.
Strong or soft, wild ore serene - wherever breath flows, there is song. (Vijnana Bhairava Tantra)