Blender is available at:

http://www.blender.nl/

(This is the official site)

Blender is supported by tons of tutorials and projects, many can be found using AltaVista and searching for the keywords "Blender" and "Animation" and "Tutorial".

See especially the Blender project called "Blacksmith". It is a small example of a quality animation done for Phillips Electronics in The Netherlands.

Amazingly good and the basic package is free!

Notes:

The Blender interface is like no other and takes some getting used to. F1 key is used for loading files and F2 key for saves. Blender loves a three-button mouse so plan for that as some features are unavailable without it.

Download as much information as you can regarding using Blender and plan on spending some time learning something new. This is not software you can master in an afternoon. (Well... I couldn't anyway.)