Detailed Review Of Preparation

PMP methodology is outdated vs. newer Agile frameworks.  Having a PMP certification is most useful when seeking a new employer (recruiters will differentiate on it), but will be of limited value when seeking an internal promotion or pay raise (assuming you are already a project manager) because your employer has better ways of knowing if you are a good project manager or not (your actual performance).

The PMP, when I got it back in 2011 was a best to apply for.  They requested detailed information on each and every project I had ever worked on, broken down into excruciating details by hours on each individual phase.  The application itself was extremely tedious.  The good thing is that few applications are actually audited, which means that you can use the best of your memory and won't be challenged on it unless audited.  The examp preparation itself was standard - get a book or a class to run through the material, do a lot of rote memorization, take some practice tests, and go for the exam. 

If your employer utilizes an Agile framework, forget about the PMP and get an Agile certification instead.