What Prep Book Should I Start With?

I know CollegeBoard’s SAT Books are the most similar to the actual SAT, and Peterson’s ACT Book, the one called “Real ACT” or something like that is the most accurate.

Should I start with the official books (CollegeBoard and Peterson’s), or does it not matter?

If I use the official books, then I would have a clear idea of what the actual tests would be like, but would it be better to end with them?