Google AppEngine - Go here to actually use AppEngine
Official AppEngine Documentation - Read these docs. The tutorial app is an excellent starting place
Official AppEngine Blog
Google AppEngine Group
AppEngine Team Google+ Profiles - This was posted on the mailing list
GAE Cupboard - An excellent resource for AppEngine articles
http://www.datastorebackup.com/ - backup tool for datastore
http://blog.notdot.net/ - Nick Johnson's blog (you should get to know Nick Johnson!)
AppEngine Reddit
Books:
