If you're REALLY motivated (read: bored) before the class starts, find out the text they use, pick one up and start flipping though it. The more you can familiarize yourself with various protocols, terminology, etc. and the flow of doing a patient exam (and the differences, ie medical vs trauma) will help you out, so you can focus more on learning the skills than just rote memorization where you're more afraid of getting your exam questions out of order during an eval than actually getting the information from the patient you need.
The National Registry test is a pain and many questions are scenario based given a certain set of vitals or description of a call scene, and will ask what is the appropriate intervention. Don't get frustrated when all of the answers look correct. The right answer won't necessarily pop off the screen. One item will be "more" correct or more immediately important than the others, even if it's only shades of grey, so you'll need to be able to discern priorities of interventions. Also some questions will deal with the dry uninteresting stuff in the textbook so don't skip over sections that appear stupid and boring.
I took mine in 2005 when it was still a paper exam and though I nearly aced it, I left feeling like a shithead, not knowing if I had even passed. Luckily now I think it's computer based and once you get a passing score the test cuts off, so you know immediately (or at least that's what I've heard).