How to Rotate Gears
This is a good tutorial to start with. It is fairly simple. It describes how to make gears rotate in SketchUp.
How to Animate a Rubik's Cube
This another simple animation to set up. And it shows how easy it is to rotate a collection objects in one single operation. In this case, all the cublets along a face of the Rubik's Cube rotate together about the same point and axis.
How to Make Tweens and Export a Movie
This video shows all the steps in creating an animation, from setting up the key frames, to creating the tweens and exporting the animation as a movie.
More tutorials soon... we hope.