One of the biggest mistakes you can make in prepping is to mix methods. If you're looking at a variety of books from different companies, stop now. Pick one. If it's PowerScore Bibles, that's fine, but then don't go next week and pick up Nova or something. If you decide to get a tutor, make sure he/she teaches the method you've been working on. (Better yet, start with finding a rockstar tutor and use the materials he/she recommends).