LINQ

here u can get all solution for language intergated query

http://weblogs.asp.net/scottgu/archive/2006/05/14/Using-LINQ-with-ASP.NET-_2800_Part-1_2900_.aspx

learn all technologies here

http://aspalliance.com/922_Using_LINQ_with_ASPNET_Part_1.all

http://en.csharp-online.net/Introducing_LINQ%E2%80%94How_It_Works_4

best
http://www.dotnetcurry.com/ShowArticle.aspx?ID=240&AspxAutoDetectCookieSupport=1

learn webservice/wcf
http://msmvps.com/blogs/abu/archive/2008/11/14/wcf-tutorial-and-ppt-presentation.aspx