Hi matthew1,
As David mentioned, there are many options when it comes to your GMAT preparation. It's important to define a number of details, so that you can go about all of this in the most efficient way possible:
1) What is your goal score?
2) What schools are you planning to apply to? And when?
3) Have you taken any FULL-LENGTH practice CAT tests yet? If so, then what did you score?
4) How much time can you commit to studying each week?
To help you set some expectations for yourself, most Test Takers spend 3 months (or more) on their studies. During that time, it's common to spend 10-15 hours per week (or more) on the process. While you don't have to study every day, it's generally better to study in small "chunks" throughout the week than to try to cram everything in on the weekends.
While many Test Takers are nervous about the GMAT, the Test is actually standardized and predictable, so you CAN train to CRUSH it.
GMAT assassins aren't born, they're made,
Rich