I used PM Prepcast videos to get started and found it as a good tool to get an overview of the PMBOK guide.
I also read PMBOK guide, Head & Rita for understanding the concepts clearly.
The Prepcast Exam Simulators is very helpful & I am very happy with their result analysis - makes you clear where you are weak (which process, which knowledge area etc). The real PMP exam is more ambiguous than the Simulators.
But it can be tackled by checking your Simulator exam results, identify your weaker areas and the key is to FOCUS on STUDYING & UNDERSTANDING CONCEPTS CLEARLY in order to clear the ambiguity when you see the real PMP exam questions.
For example - Deliverables (output from Direct & Manage Work) will go to Control Quality (become Verified deliverables) then goes to Validated Scope(become Accepted deliverables) and finally goes to Closing (comes out as final product). If you don't understand this concept clearly, you may select Validated Scope instead of Control Quality or vice versa.
As many people will be interested in knowing where we stand before appearing the PMP exam, my initial Simulator scores were around 68% but steadily increased to achieve consistently above 80% in last few exams. I would like to emphasize once again to FOCUS on UNDERSTANDING to feel comfortable during real PMP exam. One more tip, take time to read questions thoroughly and it took me around 3hrs 40 mts to complete all 200 and next 20 minutes to review marked & achieved Above Target in all areas.