I'd recommend finding Oshyan's tutorial for beginners and then finding a few other tutorials you find interesting. Then, I would get an idea about something you want to do and search here to see if someone has come close to your idea. Then, learn some more.
Eventually, you'll see there are plenty of TGDs and TGCs available here to learn about how things work. Disect these, when you're impressed with something in it, to learn as much as you can about some special way TG2 works.
It's a beginning and I like the Point of View.
