This weekend i have been reading The art of Unit Testing via the Manning Early Access Program. This book does not really teach you how to write unit tests but tries to answer those questions you start asking yourself after a while: How can i organize my tests? How do i make sure they are maintainable? Although the book is not loaded with new concepts, the existing ones are well covered. Probably one of the first books in this genre for the .Net world and most certainly recommended for reading.