There are many good yoga books are available in present like tantra illuminated yoga book, autobiography of yoga,etc. But my favourite yoga book is yoga sutras of patanjali because it is a classic that all other yoga books point back to, so if you want to read the original text, then check this book out.
Mindfulness in Plain English is one of the very best books written as an introduction to mindfulness and Bhuddist meditation. This book is a masterpiece of an extremely skillful offering of kindness, clarity and wisdom to drink from.