The Kaplan book had a CD with a few practice tests. I think I did 2. If for no other reason, they are super useful for figuring out how to pace yourself.
The math section was (is?) easy for most people on this site. This seems the norm because the score/percentile relationship was incredibly high.
The English section kills people. My pro-tip is, in the same Kaplan book, they have a list of the most common words. I made flashcards for the top 100, and I'll be damned if like 80 of them didn't show up on the test. I imagine this is similar for the SATs.