A lot of guru's and experts (in- and outside Microsoft) created a guide that provides design-level guidance for the architecture and design of applications built on .Net. It is designed to be used as a reference resource, or it can be read from beginning to end.

Why they wrote this guide (quote):

Design more effective architectures on the .NET platform. 
•  Choose the right technologies for your particular scenario.
•  Make more effective choices for key engineering decisions. 
•  Map appropriate strategies and patterns. 
•  Map relevant patterns & practices solution assets

Definitely worth checking out!

link