depends on what you're looking to do. Are you looking for more of a developer/programming perspective? or an animation perspective?
for programming: start here(codingforums), actionscript.org, gotoandlearn.com, and adobe.dev
for timeline animation: watch the multitude of videos on youtube, Lynda.com tutorials, cartoonSmart(he's fast though), etc..
the best thing is just to get in it and muck around:
draw a box with the drawing tools, tween it on the timeline, and learn to affect it with actionscript..