Probably the nexus for all things Flash is FlashKit -- http://www.flashkit.com/
-- unfortunately, the site may be slow. They seem to be having difficulty keeping up with the traffic load.
Flash does have a steep learning curve, though, so it's good to pick up a book or two: I recommend Flash 5 Magic
and Foundation Flash 5
. There are lots of bad books, so do your homework first. I just picked up the Flash 5 Bible
but it looks like they didn't proofread that text very carefully... lots of errors in it. Likewise, there were a lot of errors in the Flash 4 f/x and Design book I bought a while back... so I steer clear of Coriolis Group titles whenever possible. I never buy books from Macromedia, because I think that just encourages them to write cursory manuals so they can sell more comprehensive "books" later.