There seems to be so much information to learn. How should I start to study?

I'd start with a couple of different review books. A review book tends to organize information in a concise manner for the reader and keeps you from being distracted by extraneous information or topics that you're not likely to see on the certification exam. If the information in the review book is something that you're not familiar with, I'd use a textbook or my notes from school to clear the issue. A textbook is too comprehensive to use to study for your exam.