There isn't some magic website address and you're question is too brief for me to tell what you really want...but key to dealing with JSON is the DataContractJavaScriptSerializer class that can read/write JSON.
(If this has answered your question, "Mark as Answer")
Shawn Wildermuth
C# MVP, MCSD, Speaker and Author
Silverlight 2 Workshop
October 22-24, 2008 - Atlanta, GA
November 3-5, 2008 - San Diego, CA
http://silverlight-tour.com