Basic Flash Animation in Flash CS3
This Flash Tutorial quickly goes over Onion Skinning, Layers, Embedded Animations, Motion Tweens and finally Shape Tweens. This isn't an in depth tutorial, but hopefully it might make things a bit easier for you.
The Basics of Flash Animation
This video is a couple of years old but is great for a concise and basic understanding of Animating in Flash. If you are just starting out with Adobe Flash then this will get you started!