Another one in the Pragmatic series. Nice introduction to Unit Testing and NUnit. I chose it over some of the others because it was relatively short. :)
Amazon: http://www.amazon.com/dp/0977616673
Would the information in this book apply to MSTest as well? I'm new to testing and I'm looking to use the Microsoft testing framework.
The book uses the NUnit framework specifically, however the concepts are the same and it shouldn't be too hard to figure out how to do it in MSBuild (for most stuff, it's really only a matter of different attributes).
Additionally, I have a blog post that discusses how you can use conditional precompiler statements to switch between the two (i.e. use the same attribute names).