Can anyone share helpful links or examples?
There is a sample for accessing the calendar API, you can find it here.
It is a good starting point on how to roll you own XML mapping and use the google-api-java-client for accessing Google APIs that have not yet migrated to the new infrastructure. Based on this, I am using the google-api-java-client to talk to the Google Contact API.
UPDATE: there is a more recent example in the samples repo, look for the PicasaClient.java