Osho writes very comprehensive books in a very wide range of spiritual topic and on spiritual techniques. Including Yoga, Meditation, Buddha, Tao, Tantra, Zen, Sufi, Jesus and much more. Whatever you are drawn to try it. The ebooks are free!
Hatha Yoga Pradipika
Yoga Sutras von Patanjali
You can find many kriyas and meditations brought to us by Yogi Bhajan here:
Maya Fiennes on YouTube
The Ayurveda Encyclopedia. Natural Secrets to Healing, Prevention and Longevity by Swami Sada Shiva Thirtha