This is a list of timeshare websites that might be useful as you research buying a timeshare resale. It's a mix of official sites, owners sites and timeshare owners forums and anyplace else I think might be useful.
MouseOwners.com is a message forum for Disney Vacation Club owners. They have lots of great resources for making the most of your DVC membership and of course everyone gets to talk about their upcoming trip plans.
WorldMark, the Club is the official website for the Worldmark Points program, designed for both current owners and potential owners. Definitely useful for investigating properties and finding out how the Worldmark program works. You can also find out current retail prices so you have a frame of reference to compare auction deals for buying Worldmark points on resale.
WMOwners.com is a Worldmark Owners forum that is independent of both Worldmark and Wyndham. While it is designed for people who are already current Worldmark owners, if you are thinking about buying Worldmark points it makes sense to do some investigating here. There are lots of nitty gritty details about how the system works, how to get the most out of it and there are tons of resort reviews as well. Everyone is very helpful and friendly too.