Charmed Life: Short review of the book.
Chrestomanci Castle, or Travels in the Land of Ingary: Site dedicated to Diana Wynne Jones. Structured like the moving castle, it has discussion archives, a bibliography, news, letters from the author, links and a wiki.
Diana Wynne Jones: Brief description of each of her series.
Diana Wynne Jones: Official site. Includes a glossary of the Related Worlds, information on new books, articles and talks by Diana Wynne Jones, a detailed FAQ, and reviews and stills from the BBC production of "Archer's Goon".
Diana Wynne Jones - Yahoo Groups: Yahoo category of discussion forums about Wynne Jones and her books.
Sirius Recommends: Bibliography with a description of most of her books.