The official documentation has moved to http://docs.couchdb.org — The transition is not 100% complete, but http://docs.couchdb.org should be seen as having the latest info. In some cases, the wiki still has some more or older info on certain topics inside CouchDB.
General Tutorials and Overviews
Relaxed.tv — A collection of video tutorials and presentations
Using Views: Learn all about CouchDB's Map/Reduce views
Tutorials for Specific Languages