Any good books for Unit Testing?

Question

hi,

1)
I'm looking for good books published on Unit testing (specially Developer Unit testing) for VB or C# code (preferably C#)

any suggestions?

2)
I have found out that the Unit testing provided by the VSTS is similar to NUnit testing but they are not...., As developers we have two options either to use NUnit testing tool or VSTS testing tool, which tool would you suggest to use?


cheers