Lane LiaBraaten goes through a tour of resources available to developers for OpenSocial.

OpenSocial home on code.google.com: code.google.com/apis/opensocial
Orkut home on code.google.com:
code.google.com/apis/orkut
Orkut developer's guide: code.google.com/apis/orkut/docs/orkutdevguide.html
OpenSocial blog:
opensocialapis.blogspot.com/
OpenSocial forum:
groups.google.com/group/opensocial
Orkut forum:
groups.google.com/group/opensocial-orkut
Issue tracker, sample code:
code.google.com/p/opensocial-resources/