Experience from studying for PE Electrical/Electronics: I started about 8 months prior to the Oct 2011 exam. During the first 6 weeks, I reviewed much of the math that I thought I'd need once I started doing problems. The math review was helpul also in terms of getting familar with integral tables, transform tables, etc. I used ENSYS quite a bit during this period. Ater that 6 week period, I did very problem I could get my hands on from the Internet, textbooks, and ENSYS (ENSYS started being less useful as I moved through the variuous topics b/c their content was not keeping pace with my progress). To sum up: review the fundamentals enugh to convince yourself you know it an then do sample problems, problems, and more problems.