The exam simulator here has the best mock exams I've found. I tried a handful of others but none of them were as close to the actual exam as the ones here. It is definitely worth the money, in my opinion. I took all of the full 4-hour mock exams here and reviewed all of my incorrect answers to understand why I got them wrong. That's the great thing about the exam simulator here - it explains all of the answers so you can better understand the material. If you spend a few weeks doing these things (assuming you've already read the PMBOK and taken a class), and get to the point where you are scoring over 85% on the exam simulator, you will be well prepared.
Emily, I am about to go in and take my test before end of FEB this year. I had the same concern about the agile book. Thanks for your response- it was comforting. I do have more questions, do you have any recommended sites for mock testing? How/when did you know you were comfortable to take the test?
I took (and passed) the exam about a month ago, and I did not ready the Agile guide at all. I do not recall any detailed questions about agile; only general questions that one would know the answers to just from reading and understanding the PMBOK.