.:Book Links:.

His Dark Materials
Bridge to the Stars - Best site for information about books, and news about upcoming books.
HisDarkMaterials.org - News, Info, interaction and much more!
DarkAdamant
His Dark Materials - Cute site, where I got the picture of the alethiometer from.

The Chronicles of Thomas Covenant
The Land - Great site for information, has a lot of content
Kevin's Watch - Discussion Board on The Chronicles of Thomas Covenant

Harry Potter
Godric's Hollow - Huge gallery
HP-Lexicon - Directory of all things magical in the HP world
The Leaky Cauldron - News site
JKRowling.com - Official Site of JK Rowling

Abhorsen Trilogy
Garth Nix: Garth Nix's own site, has news about his books and such
Official Sabriel Site: Has a lot of information on the Charter, and a game.