“Yoga Sutras of Patanjali” - this book is collection of ancient, foundational texts of Yoga.
“Hatha Yoga Pradipika” - by Swami Swatmarama, a disciple of Swami Goraknath. It is a classic Sanskrit manual on Hatha Yoga. Said to be the oldest surviving text on Hatha Yoga
“7 Spiritual Laws of Yoga” - by Deepak, M.D. Chopra, David, M.D. Simon
“Jivamukti Yoga” - by Sharon Gannon and David Life
“Meditation yoga” - by Acharya Bhagwan Dev
“Cutting Through Spiritual Materialism” - by Chogyam Trungpa
“Ashtanga Yoga - The Practise Manual” - by David Swenson. It is an obsolute necessity if you’re seriously thinking to develop a regular Ashtanga yoga practice
“The Art of Yoga” - by Sharon Gannon and David Life. Beautiful pictures, amazing texts that will make you think a little about your practice and motivation
“Asana Pranayama Mudra Bandha” by Swami Satyananda Saraswati - an excellent guide on some of the basic elements that make your yoga practise.
“Kundalini Tantra” by Swami Satyananda Saraswati - defining and explaining kundalini, chakras and kriya yoga, kundalini awakening, including the side effects of such experiences and ways to both elicit and manage them.
“The living gita” commentary by Sri Swami Satchidananda - the complete Bhagavad Gita - a classic scripture of the East, interpreted for modern readers.
“Freedom: The Courage to be Yourself” by Osho - identify and overcome the obstacles in the path to be yourself.