Thank you all for the great replies, I stopped by my school's library today and looked for the books recommended. I didn't find any but did come across a few regarding mixed gas diving. I'm assembling a list of books to order and hopefully find cheap copies of (The Tao of Survival Underwater looks particularly interesting, but at $100 it's a tall order). The Essentials of Human Factors in Diving also looks pretty good, and will be going on my list.
I hear you on the cost thing, I started tech diving after uni also with limited money/resources which is part of the reason why I don't think you see many younger generations getting into tech diving or pursuing much further then AN/DP as it is just to costly so I'm always wanting to help those out that want to get into it but find some of the resources expansive. PM with your email and I can share some articles etc on tech diving and cave diving.
The best way I have heard it is, "An open water diver has every skill they need to go in to a cave, and none of the skills to safely make it back out."
Reading accident accounts and understating what there mistake was is a good way to learn as if you can not get in the water.
Also something else that you can do that is free is start doing research on instructors and contact them, ask questions, etc. You mentioned you want to work your way to full cave. At this level of diving most people start seeking instructors for there reputation because its the stuff those guys teach you that is not in the books that people want to learn.