Hi femaw,
It sounds like you're just starting out. Is that true? Have you done any studying so far?
There are LOTS of different options when it comes to GMAT practice materials, so you should plan on doing a bit of research into the various options. Most GMAT companies offer some type of free resources (practice problems, Trial Accounts, videos, etc.), so that you can 'test out' a product before you buy it. I suggest that you take advantage of all of them, then choose the one(s) that best match your personality, timeline and budget.
If you're just beginning, then it would be a good idea to take a FULL-LENGTH practice CAT Test; you can download 2 for free from
www.mba.com (and they come with some additional practice materials). A FULL CAT takes about 4 hours to complete, so make sure that you've set aside enough time to take it in one sitting. Once you have those scores, you should report back here and we can come up with a study plan.
To help you to establish your own expectations, you should know that most Test Takers spend 3 months (or more) studying for the GMAT; during that time, it's common to spend 10-15 hours per week on the process.
I'd like to know a bit more about your timeline and goals:
1) What is your goal score?
2) When are you planning to take the GMAT?
3) When are you planning to apply to Business School?
GMAT assassins aren't born, they're made,
Rich