I am in the same boat as you- I took the Kaplan course and it was not beneficial to me. It seemed like they only taught the strategies to approach and answer the questions faster...assuming you already know the material. So, I would not recommend Kaplan for you.
I scored a 490 in January and found out mid March that if I want to get into the program I need to retake it and get closer to the average of 610....So that left me with a month to study, on top of full time school in senior level classes. But, if you have a goal and know that a 550 will be sufficient for OSU MBA then you can do it. I would recommend buying all the Manhatten GMAT guides, going over them twice, understanding everything and all the tricks they show you. After that, you should have a fair understanding of the fundamentals so attack the OG#12 and the OG quant and verbal supplements....go over every question two or three times and make sure you know why you got a question wrong. When I do sentence correction, I write out all the questions I miss in a word document and explanation why I did it wrong, the rule, etc.
Keep in mind, when you do the OG questions- mainly the quant- the explanations will sometimes be too long and impractical for you to actually do on test day. If you have any doubt on a question, search for it in the BTG forum (nearly every question from OG is asked on BTG). You will develop better shortcuts and gain a better understanding for WHY the problem is done the way it is then reading the terrible, lengthy explanations in the OG.
Of course, fit in some practice. Take both the GMATPREP CATS, understand all the missed problems...review some more....and then go back and do them again (you might get some repeated questions, but its fine).
Don't forget the importance of notecards either- write down all the rules on flash cards and it will help sink into your brain by constantly reviewing them.
The essay portion probably isn't required for OSU part time MBA, so you can use this time during the test to write down any rules, formulas, notes that you might forget due to nerves or time constraints. Even if the essay section is required, you can still write down notes during the extra minutes.
As others have said, the Manhatten CATs are tough and scoring is off (obviously, no one knows the true algorithm) but if you prepare with tougher questions and understand them, the real GMAT should be somewhat of a relief- keep in mind though, that to reach the higher difficulty questions on the GMAT you have to get all the easy, fundamental questions right! So don't make the mistake of studying the advanced stuff if you aren't 100% sure you can ace the easy stuff.
Good Luck!
Jason
