A friend just wrote and asked me if I knew of a list of writers conferences and residencies. The best one I know of is the one at Poets & Writers: Conferences and Residencies. It’s pretty thorough, I think, and has pretty detailed listings.
For example, here’s the listing for the Sewanee Writers’ Conference (a social event for which is pictured with this post). And, of course, the listing includes a link to the conference’s website, for more complete and current information.
AWP also has a good directory, which is here: Directory of Conferences & Centers. (The listing for Sewanee is similar but not identical to the one in P&W.)
So if you’re looking for a writers’ conference or residency, those would be the first two places I would check. If you know of other lists or guides, please mention them in the comments below.
ETA: Shame on me for forgetting about another great list, this one maintained by New Pages. Check out their Writing Conferences & Festivals page!