I hate to quote Wikipedia, but it has a basic list here:
Honestly, though, I wouldn't recommend them for learning much without a lot of relevant hands on.
IMO, the language that O-Sensei used is important for what it points to - a shared methodology. For much else you have to go to the people themselves.
In case anybody's wondering, the "you" here (as in "you have to") is meant to be generic.