I would try and focus on what you want to do with flash as it is darn deep. With that in mind I think that a combination of video tutorials and good books works nicely. Online there is Lynda.com, LearnFlash.com, CartoonSmart, Actionscript.org, and Kirupa to name a few. Those will get you started.
As far as books I've found the Friends of Ed books to be exceptional.