Skins81- I bought the Official Guide and the Kaplan GMAT Premier books from Amazon, they were about $30 each. Buy the Kaplan book new, it gives you access to their online material (the CD is useless on newer computers) which gives you a few practice tests and a bunch of quizzes. You can't access it if someone already did, so a used book is half worthless (good business plan by Kaplan I suppose). The book itself is good because it'll give you some strategies for recognizing problems quickly and how to go about solving them. The Kaplan book also references the Official Guide for problem types, so use the Kaplan book first. I started with the official guide and I think I wasted about a solid week of studying- in that book you learn the academic way to problem solve, not the 2-minutes-or-less way like Kaplan teaches. I also logged my hours of studying in Excel and kept track of what subjects I studied to make sure that, at least initially, I was devoting equal time to all study matters (even subjects I considered my strength). My goal was to study for 114 hours; I had read somewhere that that's some golden number for getting 700+. I'm not sure about the validity of that claim but it served as a reasonable target, and by the time I was done taking all the practice tests I was up to about 150 hours. A friend gave me some Manhattan GMAT smaller manuals about a week before my test but I found them to be way too elementary compared to what I had been studying.
After taking your first 2 practice tests and a couple of quizzes, you'll know if there's an area that will require more focus. I would still advise reviewing subjects in which you feel fairly confident, maybe just tackling the harder problems (higher numbers in the Official Guide).
I didn't spend too much time on the AWA practice- the practice tests will have questions for you to answer. The guidebooks give a general format that you should follow. I just did the essays on the practice tests. My advice for that is to not dive directly into a topic (for the analysis of an issue), but rather to outline different sides why you would be for or against something. This is effective for a couple of reasons- you need to show a strong point for the other side anyway (before countering it of course), and it helps you figure out what you can write about more. I was surprised during my actual GMAT that I had much more to write about supporting what I thought would be my opposing side than I did for what I wanted to advocate. As a result, I just switched sides- you can do that since there's no right or wrong answer, you just need to convince yourself (which is probably the hardest part, so keep an open mind). I got a 6 AWA so that strategy worked.
I also found the flashcards available on this site to be incredibly helpful. I came across this community about halfway through my studying, and I think my time would've been more efficiently spent had I come across it sooner. I stopped studying, spent a couple hours just topically going over all of the flashcards, then continued studying so that they all made more sense. Kaplan will give you a little cheat sheet of shortcuts you should know, but also memorize the math shortcuts on the flashcards. I found the divisibility rules tremendously helpful on the actual test- I don't think I would've finished the math section without them.
Lastly, something I'd recommend is to pick up the actual write-on board and marker that is used on the test. I was using a 0.7mm pen and thought that it would mimic the actual pen at the test. Not even close. You're going to leave the test looking like a 5 year old playing with crayons, especially if you have a habit of rubbing your face like I do. It matters because if you write small, it's annoying to have to learn to write large during the test.
I didn't sign up for the Kaplan class that I wanted because I had been out of work for a while and I didn't know when I would start receiving a paycheck again, and $1500+ was a lot of money. I probably would have scored a little higher with a course, but I don't know for sure.
Oh and don't get discouraged on the first diagnostic test, most people don't do well. I think I got around a 500 on it. The MBA.com practice tests seemed to yield ridiculously high scores- I got a 760 on that after consistently scoring between 690-730 on the Kaplan practices.
Hope this helps. Good luck!
