I don't know about your situation and what you feel comfortable with but this is the way that I have/am preparing for the exam:
1. First I spent about 3 to 4 months learning the basics of
Java through Ivor Horton's Beginning Java 2. This taught me all of the basics and had some great coding examples.
2. Now I am reading RHE to study specefically for the exam. Having read Ivor's book, this is just a refresher and points out the main areas that I need to know and need to study.
3. When I finish this book, I am going to start doing all the mock exam I can get my hands on. My guidelines are going to be that I want at least a 95% on all the mocks I take. If I don't get a 95%, then I will study on what I missed and wait a week or two and take the exam again.
4. After I have taken as many mocks I can, I am going to read the exam cram about 2-3 weeks before I take the exam. I'll take a few more mocks as final prep, and then I will take the exam.
But my goals my be different than yours. My goals are to learn Java first and most importantly. Second is to pass the exam with 100%. I know I probably won't get that high, but I agree with some things that Tony Alicea has said and you go in with the expectations of getting 100% because that will maximize your score. If you go in saying all I care about is passing with 61%, then the most you will get is 61%. I have taken the CPA exam (accounting not technical. Yes I used to be an accountant) and that was the thinking I went in with that exam. I was going to pass all 4 parts my first time sitting, and when I got my scores back, that is what happened.
Good luck to you,
Bill