<Under Development>
What is RIA Services
http://ashwini47-tts.blogspot.in/2012/08/what-is-wcf-ria-services-and-when-to.html
http://stackoverflow.com/questions/3684421/what-is-wcf-ria-services
Getting Started Tutorials
MSDN http://www.silverlight.net/learn/advanced-techniques/wcf-ria-services