WPCandy tutorials – WPCandy has many useful tutorials that provide tips on configuring your blog.
FLOSS – general how-to manual for WordPress (in TWIKI format)
WordPress.org – Here you will find complete documentation for WordPress, including available plug-ins and themes and free downloads. As an open source project, WordPress depends on its community to develop plug-ins and themes, and to document each of these by using its Codex, a collection of blog pages which serve up wiki pages that members of the community can collaborate on.
WordPress TV Screencast how-tos created by WordPress developers