DataBase Design Demo
http://www.databaseanswers.org/data_models/index.htm
http://code.msdn.microsoft.com/Getting-Started-WCF-RIA-1469cbe2
http://www.silverlightshow.net/items/Building-N-Tier-business-applications-with-WCF-RIA-Services-Part-II.aspx
http://www.cnblogs.com/shanyou/archive/2009/12/13/1622932.html