Welcome to the site. My advice to you would be to start by identifying your strengths and weaknesses. Then bolster your knowledge of basic concepts by doing practice problems from the OG11
. Track your progress by taking full length CATs. Then as you get closer to your test date start to take more practice CATs to help with your concentration and pacing. Participating on the math and verbal forums is also a good way to improve. Check out my GMAT experience
if you want to see how I prepared.
Profile | GMAT | Erb Institute