Hi sq01,
If your prior attempts at studying for the GMAT were not enough to get you to your score goal, then some adjustments will have to be made. Since it's been so long since you were in 'study mode', you're essentially going to start from scratch (although you do have some content knowledge that you can draw on, so certain aspects of the study plan will likely be easier to work through).
Before I can offer more specific advice, I'd like to know a bit more about your prior GMAT attempts and your timeline/goals:
1) How did you score on each of your prior GMATs (including the Quant and Verbal Scaled Scores)?
2) When are you planning to take the GMAT again?
3) What is your score goal?
4) When are you planning to apply to Business School?
5) Do you know which Schools you plan to apply to?
GMAT assassins aren't born, they're made,
Rich