If you want to be certified (for example MCTS: Microsoft Visual Studio 2008) it might be a good idea to consider some ways to train and also to assess your knowledge before doing the exam.
I got a chance to try one of the PrepKits from uCertify. I have developed professionally for many years but the way the certification tests are done and what they might cover I found that to pass I would really need something like uCertify.
Below are some screenshots of the interface. I found it to be intuitive and easy to use.