Getting Started Read this document to learn the basic steps involved in developing Android applications based on GCM.
Architectural Overview Read this document for a description of the underlying concepts and architecture in GCM.
Demo App Tutorial Read this document to walk through setting up and running the GCM demo app.
Advanced Topics Read this document to get a more in-depth understanding of key GCM features.
Migration Read this document if you are a C2DM developer moving to GCM.
GCM also provides helper libraries for client and server development.