My ds took the SCAT in 6th grade. He was able to take it in a Prometric Testing Center, which had lots of cubbies and was pretty quiet (Prometric, here anyway, is mostly for things like professional licensing exams, so the crowd is pretty tame, age 18+ and serious).
We found NO commercial SCAT prep materials. To my mind, the big task was just to get him comfortable with the instructions and the expectations of the test. So we sat down and went through the CTY samples. Then I wrote a couple of additional problems based on the CTY samples, just so he could feel comfortable with the process.
Other than that, you could do vocabulary prep, since the verbal is all analogies (as I recall). We did not do anything like that. The math is quirkier; not sure there's any way to prep beyond understanding the instructions.
