This is a series of video tutorials I've found online which will give you the basics to create cartoons for animations and games using Flash:
Squash & Stretch
This is a basic animation technique you should understand before going into more complicated stuff.
Lip sync is how you make your characters talk. There are several ways you could do this. One is very simple or "Jib-Jab" style, the other one requires you to implement phonemes (mouth positions).
Animating with Symbols
A very important skill every animator should have is how to organize his symbols for animation.
The bone tool allows you to apply Inverse Kinematics