Is it better to go through a GMAT book like PR or Kaplan
all the way through and then use the Official Guide seperately, or is it better to mix them together.
I guess it's dependent on how you like to study. As for me, I went through PR then Kaplan
. After those two, I did the Power Prep Exams downloaded off the mba.com website, then the OG.
I did this because I wanted to build up basic test skills and practice before tackling the real thing. Not sure if you did Power Prep yet, but the other thing you might want to keep in mind is that the Power Prep test is made up of questions from the OG. If you want the closest approximation to the real GMAT test, it's probably a better idea to do PP before OG. So, the only practice questions you get (without compromising the results of the PP test) are from guides like PR and Kaplan