This article was written awhile ago but got stuck in our MSDN Editorial queue (with about 10 other articles still sadly) but they are coming out -- if you are interested in Standards based design this article does a great job of explaining how things in ASP.NET 2.0 work and how to build those sites to be standards based.

Check it out here at: http://msdn.microsoft.com/asp.net/default.aspx?pull=/library/en-us/dnaspp/html/aspnetusstan.asp