Acquire the essential of Srila A.C. Bhaktivedanta Swami Prabhupāda's library, with these seven must-have titles:
 
1. Bhagavad-Gītā As it it
2. Śrimad-Bhāgavatam, First Canto, part One
3. The Nectar of devotion
4. Teachings of Lord Caitanya
5. The Journey of Self-Discovery
6. The Science of Self-Relization
7. Krishna, The Supreme Personality of Godhead

On the basis of these seven litteratures, you will get a clear understanding of the ultimate goal of yoga practices, and the means by which we are meant to achieve it.