The #2 pencil is overrated. All you need these days is 2 fingers...
Seriously though, I'm also about to take it and I've gotten a wide range of advice, ranging from "don't worry--it's impossible to fail" to "read up on all the basics" to "do as many questions as possible."
The only consistent advice was to make sure to familiarize yourself with the case simulation scenarios (provided on the CD you get when you register) in order to save yourself some time and headache on day 2 of the test.
I havn't taken it yet, but I would study that which you don't see in your internship (OB, Peds, preventative med, etc.) First Aid for Step II would probably be decent preparation - what are they going to ask that isn't in there?