The Spiritual Side of Life. Part 1.

The spiritual aspect of life is both the most complex and the most useful. Almost everything "spiritual" that you do has carryover to almost every other aspect of life. This is due to the fact that the basic spiritual exercises deal with the control of breath, the control of mind, the control of nature, the development of intuition, and the development of what can be called "life force."
I'd like to deal with each of these in their own place at a later time, but for now I'd like to go over what's obviously necessary for gaining a decent intellectual grasp of the whole matter.
Reading a spiritual text is often a developmental exercise in it's own right. The carryover isn't as great as some of the other exercises but there is still a whole heap of benefits. For instance, prolonged contemplation of texts like the Tao Te Ching or Liber AL will eventually lead to certain very "useful" realizations like the benefits of the path of non action, the power of love, true morality, and a lot of other very profound "secrets of life". Someone whose inclination is heavily intellectual could probably achieve a high level of realization just from contemplative readings, but it's my opinion that there are much more efficient (though sometimes significantly more uncomfortable) ways of attaining the same result.

For today though I'd like to give a brief outline of the specific texts that have helped me on my way. This list is by no means complete. For instance I've never really studied Islam, Voodoo, Santeria, the Essene traditions, Alchemy, Rosicrucianism, and a ton of others. I fully intend to at some point, I just haven't yet.

To start you should get a taste for everything.
I think it's a really good idea to realize that all religions are essentially the same with the only differeces coming from terminology.
This list is more or less copied from the general reading list of the brotherhood of A:.A:. Most of these texts can be found for free online through Sacred-Texts.com

Study the Taoist traditions with Lao Tzu and Kwuang Tzi.
The Buddhist traditions with The Suttas and The Dhammapada.
The Hindu traditions with the Bhagavad Gita, The Upanishads, The Vedas, and the books on Yoga (Siva Samhita, the hathayoga pradipika, the Aphorisms of Patanjali, and Raja Yoga by Vivekananda).
The Christian traditions with the Dead Sea Scrolls, the Pistis Sophia, and the spiritual guide of Michael Molinos.
The Thelemic traditions with Liber AL, Liber ABA, Liber Aleph, The Equinox, and The Confessions of Aleister Crowley (just to name a few).
The Qabalistic traditions with 777, The Book of Thoth, and the works of Eliphas Levi (which will also give you a fair grounding in Hermetic traditions). Qabbalah has a mixed heritage so you might also want to study some of the Lurianic texts to get the Jewish side of things, but from what I've studied the Hermetic tradition is both clearer and more complete (mostly due to Crowley's contributions).
Also the pantheons (taking each god and goddess to be a representation of either a force of nature or an aspect of the human condition) of all the pagan traditions, esp. the Egyptian, Greek, and Hindu.

This is a very good foundation of reading and if you are diligent you'll be different person when you're done.