You can find information to configure GateIn in the following pages:
http://www.jboss.org/gatein
http://docs.jboss.com/gatein/portal/3.1.0-FINAL/reference-guide/en-US/html/index.html
The complete GateIn documentation is in this page:
http://www.jboss.org/gatein/documentation.html
If you need other information or if you have problems during the configuration you can use the GateIn Forum.
Hope this helps.