http://www.asp.net/learn/dataaccess/default.aspx?tabid=63
http://www.cnblogs.com/webabcd/archive/2007/02/04/639830.html
Configuring .NET: http://www.developer.com/net/asp/article.php/3569166
ASP.NET访问层: http://www.souzz.net/html/edu/net/net1/13338_9.html
.NET Web Service: http://www.15seconds.com/issue/010430.htm
Files: Applications: http://wf.netfx3.com/files/folders/sample_applications/default.aspx
多层应用: http://dev.csdn.net/article/77/77536.shtm
