Cool Tolkien Link of the Week (3/23/06)
Probably the best fan site to compliment both the books and the films is TheOneRing.net.
This site was created after the announcement of the film project and chronicled every aspect of it from early rumors to DVD release. It continues to follow the comings and goings of every actor associated with the project as well as major contributors such as Peter Jackson, Howard Shore, Alan Lee, John Howe, Weta Workshop, etc.
The webmasters are a group of rabid Tolkien fans. Be sure to check out the Green Books section for fascinating original work by the contributors!