Whether you're new to reading the Booker Prize, or a long-time devotee, the following sites may be of interest:
Man Booker Prize official site: news, author interviews, and archives of winners, shortlists, and longlists.
Yahoo BookerPrize Group: As described on the group's homepage, this reading group reads "one novel a month, choosing from among the long-listed, short-listed and winning novels of the Man Booker Prize, honouring the best British, Irish or Commonwealth novels each year. "
LibraryThing: For LibraryThing members, there are three library catalogs containing Booker Prize nominees and winners through 2006. This is an easy way to locate and add books to your own catalog!