Hi all, I just started preparing for the PMP couse and I just started reading the PMBOK.

I notice most reference books, such as the book by Rita, the Headfirst book, etc contains details by each knowledge area, while other book eg, the book by Kim Heldman contains details by each process groups.

Which is a better way to study? Not sure which one is more suitable. Would you give any suggestions or comments? What are the advantages / disadvantages?