Wikis in Plain English video
Wiki Matrix (allows you to compare many different kinds of wiki software-the review article Which Wiki is Right for You? should be helpful when selecting your software)
Web Tools 4u2use: Wikis (lots of excellent school library-related examples)
Wiki Wisdom: Lessons for Educators
Four Letter Words: How Wiki and Edit are Making the Internet a Better Learning Tool (one chapter from an e-book that has been created using a wiki)
10 Reasons Why Your Next Pathfinder Should be a Wiki (blog post by Joyce Valenza)
School Library Learning 2.0: Week 7, Wikis
Getting Tricky with Wikis (this site has terrific ideas to take your wiki to the next level)