i want to start writing unit tests for my project, what add ons if needed should i install, what abilities do i get by default?
I highly recommend NUnit, even over Visual Studio's built in tests.
Here are some more references:
NUnit vs Visual Studio 2008’s Test Projects for Unit Testing?
NUnit vs. MbUnit vs. MSTest vs. xUnit.net
More importantly, manage your expectations and understand where these tests make sense and where they don't. It'll help keep you from getting discouraged as you're getting started. Searching Stack Overflow for unit testing and/or TDD will give you lots of food for thought.