Well let me be the first to welcome you to the GMATclub. I promise you, you'll find everything you're looking for right here. First, it sounds like you need a study plan, so why don't you take a look here:
gmat-study-plan-start-your-gmat-journey-80727.html This is one of the best study plans every compiled, and it will definitely help point you in the right direction. Now since you have 2 months, I would recommend that you start studying as soon as possible, and make an effort to collect a couple good books for your studies. I would also recommend that you take a diagnostic test so you know exactly how much studying you will need to do to attain you 600. For instance, if you score a 570, then your almost there, but a 370, and you've got a good bit of studying ahead of you.
Once you've had an opportunity to do both of those things, follow the study plan to attain your goals. Dive into the GMAT head first, and put your all into it so come March, you'll be done forever.
Come by and ask any questions you need, or search the forums for help. Best of luck on your GMAT journey!
PS. the
OG guide itself will not be a strong study tool on its own. It is a collection of real practice questions though which will help later in your studies. Practice questions will not get you ahead, but the mastery of the topics, strategies, and questions will, and then practice of these question of course. The
OG has very basic explanations, and could leave you more confused if you're using it as your only means to learn. Start with the very basics (Refreshers) and then work to the more advanced. Only needing a 600 means that you don't even have to get the hardest of questions correct. Good luck!