Validation Application Block

If you are looking for one stop article to understand the Validation application block , check out this article :

http://msdn.microsoft.com/en-us/library/ff953182(v=PandP.50).aspx

Also download these hands on Labs :

http://www.microsoft.com/downloads/en/details.aspx?FamilyID=2C34A9CB-17CF-4AEC-8DE6-EEACBBB74413