Here is my lessons learnt from PMP exams:

I read twice PMBOK and Rita's book. I also read some contents from PM Road Trip .My preparation period was 3 and half month. PMBOK was very usefull and I took few test exams:

Here are scores for test exams:

Rita fast track exam: 69%(First exam)

Rita's fast track exam : 75% (Second exam)

PMStudy : 80%

HeadFirst 200 Qus: 81%

Oliver 175 qus : 78%

Exam central pool : 84%(first 200)