Personal reminder: I’ve found these couple of posts very useful:
WCF & RIA
http://blogs.msdn.com/saurabh/archive/2009/11/23/understanding-the-wcf-in-wcf-ria-services.aspx
RIA Endpoints:
Deployment:
http://blogs.msdn.com/saurabh/archive/2010/03/16/ria-services-application-deployment.aspx