Today I was pointed to the following document on MSDN. It is a good read, and a must for anyone wanting to exploit the .NET framework to get the best code possible. It also provides a lot of background information on how the framework works.
http://msdn.microsoft.com/library/d.../dndotnet/html/dotnetperftechs.asp?frame=true
http://msdn.microsoft.com/library/d.../dndotnet/html/dotnetperftechs.asp?frame=true