Read the Bhagavad Gita, its a classic.
Also check out Kashmir Shaivism.
Also Yoga Sutras of Patanjali:
1.17. Cognitive meditation is accompanied by reasoning, discrimination, bliss and the sense of 'I am.'
1.18. There is another meditation which is attained by the practice of alert mental suspension until only subtle impressions remain.
1.19. For those beings who are formless and for those beings who are merged in unitive consciousness, the world is the cause.
1.20. For others, clarity is preceded by faith, energy, memory and equalminded contemplation.
1.21. Equalminded contemplation is nearest to those whose desire is most ardent.
1.22. There is further distinction on account of the mild, moderate or intense means employed.
1.23. Or by surrender to God.
1.24. God is a particular yet universal indweller, untouched by afflictions, actions, impressions and their results.
1.25. In God, the seed of omniscience is unsurpassed.
1.26. Not being conditioned by time, God is the teacher of even the ancients.
http://www.sacred-texts.com/hin/yogasutr.htm