Please have pity on your future PowerScore instructor and do not take the Princeton Review course.
I have been teaching and tutoring students for 3 years now after having received a 180 on the Dec 2005 LSAT-- the last year through PowerScore. I can't tell you how many students have come to my classes or had me for tutoring after having taken a Princeton Review or Kaplan course and finding it worse than useless. These students always struggle 10x harder to understand things than the ones who are starting fresh.
If you want my opinion, you are better off reading the PowerScore Bibles and working through their material before taking the course if you are going to do any LSAT-specific work.
However, I think it would be even more beneficial to work through the material in a book entitled Rex Barks, which is somewhat hard to find in bookstores but which you can order on Amazon or from the publisher, since I have found that 70% of the confusion in my students comes from them not understanding how words in sentences logically relate to one another.