How to learn TGB?

So I've done a little bit of programming before, and purchased TGB and have been trying to figure it out. I've done a few of the tutorials, and can for the most part stumble through doing some stuff on my own. However, there is alot that I do not know and would like to learn. What is the best way to learn TGB? I've been doing the tutorials... but is there a certain order that is best to do them in? Any books that focus on TGB? I have registered at torqueschool.com, but with class sizes of only 20 students I am afraid that the class might fill up before I can get in. What different paths have other people here taken to learn TGB? Thank you in advance for your replies :-)