I read through the book maybe a month and a half before the exam, after taking I felt like that book gave you what you needed and a lot of filler to boot. If you can do basic cup to gallon conversions, the metric system, and how to do math with a calculator; you should be fine. The grammar/reading based questions aren't world ending take it seriously though and eliminate answers until you find the best, that will help you down the road. Knowing your anatomy as well the layers of the systems and the basic functions, the stuff you don't know make sure you know it. They ask questions from 1 and 2 and it is a long test so don't let it burn you out.