Looking through the LDD website can be a good use of time. There are plenty of tips to be found. Today I was looking through this section and found a presentation from Lotusphere 2008 on "Using NSD – A Practical Guide".
This was written by Elliott Harden and Joe Wallace.
The explanations seem pretty clear, while not suited for an absolute beginner, it is certainly a good starting point.
Semaphore debugging has never been so much fun.