It really depends on your knowledge base. When I was prepping, I found it most helpful to start by taking the quizzes at the end of each section of the ABA Reference Guide to Regulatory Compliance. Then I focused my study time on the areas where my scores showed the most opportunity for improvement. In my case, that was BSA/AML and Reg. W. For those areas, I reviewed the ABA guide, regulatory interpretations, and any recent consent orders.
Opinions are strictly my own, and have nothing to do with my employer.