Here are some links to otherresources you might find useful. Feel free to add a link you thinkwould be helpful to other developers!   

Official Documentation:   

Google Calendar API Home: http://code.google.com/apis/calendar/overview.html

Google Calendar Developer\\47s Guide: http://code.google.com/apis/calendar/developers_guide_protocol.html

Google Calendar Articles: http://code.google.com/intl/en/apis/calendar/articles

Client Libraries for GData: http://code.google.com/apis/gdata/clientlibs.html

Links to user-written tutorials, examples, and other resources:

 Provider for Google Calendar Source: http://lxr.mozilla.org/mozilla/source/calendar/providers/gdata/components/