I learned mostly from browsing youtube and bookbindng websites. Sea Lemon on youtube is a really good resource to start with, the tutorials are very well made and she explains how to make books using everyday materials.
http://www.youtube.com/user/SeaLemonDIY
Once I was a little more experienced I used the Bookbinding Chronicles to learn how to sew using a frame, and how to make larger books
http://www.youtube.com/user/BookbindersChronicle
From there I found random info that I would piece together to get the result I wanted. Also if you are near San Francisco there is the San Francisco Center of the Book that offers classes that include basic bookbinding, leatherwork, and gold foiling (SFCB.org). I am hoping to take classes there soon.
And for supplies, I use Hollanders. They have the best selection I have found so far, but they are a bit pricey. Luckly it is not hard to make a press as long as you own a drill, and the sewing frame isn't to difficult either. I was able to make both for $30 instead of paying around $400.