Gonna take it tomorrow too. It's going to be my second time so I can get "super scoring" (where you can use the highest scores in each category).
I've studied a bit for the SAT, but I'm not "naturally" good like a few people in my school are. I have that big prep book that the collegeboard made, and I took some prep classes offered at my school.
However, what I've come to realize is that you don't really need too much prep. Taking a practice test at least once before the test is helpful so you understand the "flow", but other than that, it's not too important IMO. As long as you're decent in Math (and have taken at least Algebra II and Geometry), read a lot/enough to get down the vocabulary, and are a decent writer, you'll be fine. There's nothing too "special" in there you wouldn't learn at school otherwise.
The first time I took it (back in May last year) I got a 2130 (750 Math, 700 Writing, 680 Critical reading). That's decent, but I'd like to get my critical reading up to get my score to 2200+. Hopefully!