Wim Claes shares a .blend file that he created to learn the basics of the Blender animation tools.
You can use the file to experiment with techniques such as driven keys and the NLA editor and the model is fun to work with.
That said, I think that the file could be more useful if it also provided some documentation on the setup.
You can download Squeek from Wim’s website. The file is shared under a Creative Commons Attribution-NonCommercial-ShareAlike license.
