This site hosts pre-made .blend files that go along with the Blender 3D: Noob to Pro tutorials at WikiBooks. Blender is an open source (thus *free*) 3d modeling, animation software. Its intuitive interface, the wealth of tutorials available online, and its growing community make it an apt rival to commercial software, such as 3D Studio Max, Rhino, and Maya.
Note that the files are created with the latest version, Blender 3D 2.4. Blender is available for free with no 30-day catches or anything like that. See the Blender website for more info.
Files are referenced according to the title of the wikibook entry. For your convenience, the link to the original wikibook entry is provided.
File Needed for...Mesh Modeling: Modeling a Simple Person. (Wikibooks tutorial)