Nelkum's Realms of Despair Page
  An accurate and comprehensive listing of directions, with some deity and lowbie info as well.
  A wiki containing most of the Realms information out there.
Silverwolf Realms of Despair Page
  Some random realms-related info and a post-shattering EQ database.
Guild of Mages
A lot of great miscellaneous info and some particular stuff for mages like EQ suggestions and info on paths.
The Realms of Despair Website
  The official website.