Start here:
Really general overview:

This is a good overview of the specifications:

Here are some of the standards we'll be implementing. Note that several of these documents are referenced in our target spec:

Overview of the specification dependencies and documents:

Google's instructions on using Sunbird (free/open source calendar software that supports CalDAV as a client) with Google Calendar:

This is a document that outlines the coding standards that will be in effect on all software we write:

Code resources for CalDAV and GroupDAV:


DavMail: (CalDav Gateway with Exchange)