Now having passed the PMP exam on mid-January 2014, I want to share my experience on exam preparation.
First of all, you've got to know that I'm not the kind of person who's able to memorize tons of things by heart. However, knowing the 47 processes described in the PMBoK and their respective process groups and knowledge areas is mandatory as a starting point. You've also have to know how they're tied to each others.
Here are some advices from what I found useful during preparation phase.
Have you ever tried to read a phone directory sequentially ? Reading the PMBoK one section after another will leave you with this impression. Don't do that !
It's far better to get the structure:
This being said, I favored the e-learning to get into each knowledge area (more dynamic), and refered to the PMBoK when necessary to delve deeper into some specific topics.
After the first shot of e-learning, all of this still seemed much theoretical, and I had to admit that it felt like a bit dry to me. The only way to motivate instead of falling asleep on your PMBoK is to practice. Yes ! Try yourself against real questions.
First of all, this is an active way of learning. You don't only read. You think about what is the best answer, often in the light of your experience, and compare to the expected answer. As no one like loosing a game, the reason why your answer was the bad one as well as the good answer will be better memorized.
Second, it gives you an opportunity to scam through the PMBoK with a purpose (find why the answer you gave is the good/bad one). Doing things purposefully leads also to better memorization. And if you practice enough you'll have gone trough the entire book.
And last but not least, you get accustomed to the style of the exam questions. 2 classics are:
Scordo's book, in particular, contains set of 50 questions, which allow you to practice 1 hour max, and get some feedback quickly.
After having tried to answer to a lot of questions, the fact that everything was not in the PMBoK unravelled!
Indeed, PMP exam also test general culture on project management surroundings, especially teams & HR management, some specific aspects of risk management, contracts negotiation, and so on... The only ideal back-up for helping you answer to these questions is Rita Mulcahy's book.
Although being a bit expensive, it will provide you with plenty of additional information to answer to questions, and will allow you to benefit from between 25 and 40 questions per knowledge area, just to keep on training !
Olivier F. Lehmann provides online resources on his website : http://www.oliverlehmann.com/sample-questions-pmp-self-tests.html
He especially provides a 175 questions test, as well as a sample of 75 very difficult questions.