Hello Kerfuffle,
Welcome to the group. Lyn summed it up nicely, but I'd like to add that you can also browse the blog forum for help with various writing questions. We have various events (like the one coming up in a few days) where you can pitch your book to agents and editors, where you can polish your pitch, or the boot camps that help keep you on track.
This is a good place for busy people since the classes aren't attended in real time. The instructor will post his/her lesson and you can respond when it's convenient for you. We have quite a few lurkers, but take it from me, you'll get a lot more out of the lessons if you actively participate. I'm a moderator, and I look forward to seeing you in class.