Look at the bookmarks (asp.net,c#,Linq,404pages,500pages,config files)

http://aspnetresources.com/articles
http://imar.spaanjaars.com/497/proper-handling-of-404-errors-using-redirectmode
http://blog.turlov.com/
http://martinondotnet.blogspot.com/2010/03/aspnet-and-custom-error-pages-seo.html

InterFace
http://msdn.microsoft.com/en-us/library/ms173156.aspx