I'm not sure how best to study for RC other than to practice by reading scientific articles and doing the practice sections on kaplan/topscore/achiever.
As for the QR section, math destroyer was the only book I used and needed. The actual DAT seemed to be a bit easier than math destroyer in terms of difficulty so don't be too discouraged if you don't do well on math destroyer at first. However, I can not stress the importance of timing for doing well on QR. Anyone can get most of the QR questions given enough time. You really have to strictly time yourself while practicing so you know how to pace yourself and not run out of time at the end. I literally finished the QR section with a few seconds to spare. Best of luck.