I studied decks, old exams, First Aid for the USMLE Step 1 (mneumonics only), & a high-yield outline for biochemistry obtained from upperclassmen.
I did all the old exams twice. I'm not sure how useful that time was though, as I saw relatively few repeats. Definitely focus on more recent exams (1990's & up). The ones from the 70's are a joke.
I took the computer exam, not written, so I can't speak to that. Based on my experience though the toughest part was occlusion. They asked 4-5 crazy questions about how a condyle moves in the fossa during various eccentric movements. One of my friends had the same questions while another did not, so YMMV. Path had some tough ones too, but you can't sweat those--it's simply not time-effective to memorize every single symptom of every single disease they might ask about.
Decks by far. Honestly, this is JMO but I think you're better off focusing on fewer study sources and learning them as well as possible. Don't spread yourself too thin.
I never used the 2006 version, but I knew 2004 inside & out and that was more than enough for the exam. If you have the option I would use 2006, but don't sweat it if you don't.
Don't stress over the exam. It's not that bad. IIRC you need roughly half right (or even less) to pass. You'll be fine if you have made an honest effort to study. I saw a scan of an official breakdown of scores & it showed that 2% of test takers fail. The document was from the 80's but I doubt the distribution has changed any since then. So basically that tells you it's almost impossible to fail if you try.
