Firstly the PMP handbook has been updated. The previous version's size is less than 700 KB but the new one is 1500 KB. So if you are a PMP Aspirant, this should be the first book to read.
Again - this PMP Handbook must be read by all PMP aspirants.
First of all - make sure that you are eligible and know what to expect, download PMP Handbook from PMI or from this link
If you are eligible, then start analyze yourself. The ancient Greek aphorism "Know Thyself" is needed: think about your study style, your strength & weakness, your workload and your life & professional objectives. Then sit down and inventorize those in written form (on paper or electronic document)
More here:
http://pmhub.net/pmdigest/pmhub-ads-rate/85-road-map-to-pmp