In order of importance:
Get flash to animate with. If all your doing is animation, then you can go back as far as CS4 and still have all the tools you need.
Get a hold of this book if you can.
Animators Survival Kit
Learn sound design if you don't have someone doing it for you. It will go a long way to making your animation better.
Read some basics on framing, composition, and editing. You will find this in film study.
Maybe get a Tablet, but I have known some good animators that just use a mouse, so it is in no way required.
Then again maybe you just want to get flash and screw around with it. Either way, good luck.