Welcome to EH-Net!
Nice avatar, haven't seen that used anywhere in a while...
I have taken the Offensive Security course and thought that it was a good overview of BackTrack and its associated tools. If you're not familiar with Linux or have not used BackTrack enough to feel competent with it, then I highly suggest taking the course.
All of the material is presented in a very easy way to understand and grasp how to use many of the tools included in the BackTrack distribution. There is also a lab manual that goes along with the course videos so that you can either practice in their labs (additional fee) or create your own.
If you're already familiar with both Linux in general, and you feel pretty comfortable with using BackTrack, then you can probably wait until the next course, BackTrack to the Max, comes out. OS101 is a great way to fill in any of the gaps though
Hope that helps.