Here is a few lesson learns about my journey through the PMP certification exam.
1) I started studying 2 months before the exam.
2) I bought PM Prepcast a and studied it for about 3-4 weeks. (I listed all the chapters and was also making my personal resumes about the most important concept/information) at the end of each knowledge area I always reviewed the resumes and notes which helps you to clarify concepts. - I study for about 2-3 hours each day and at least 5-6 days per week. (Double the time on the weekends)
3) After I finished the prepcast I started reading Rita's book. This book you can read it in about 2 weeks, it will be like a review of the PM concepts that you already learned on the prepcast so it should be very easy to read.
4) Do ALL the exercises/exam questions on the book, that is the main reason of this book.
5) After that you just need to start practicing as much as you can.
Make sure you do at least 2 full test (200 questions) so you can see how it feels like and make sure you can distribute your time appropriately.
Thats it. with this will be enough to pass the exam.