Take a practice test! You'll be much more effective in your studying if you know your strong and weak areas. You can download two free practice tests from the official GMAT website. The scores from these are legit since the scoring algorithm is exactly the same as on real GMAT.

Once you get that practice score, then it'll be much easier for other people to comment on your study plan. With a goal of 750, you'll have a very difficult plan if your practice score is 675 than if it's 450, you know?

Sounds like you have a great start going though, I'm about to buy Manhattan SC Guide myself, since that was my weak area on practice GMAT.

agreed, take a test first to see where you are. i dont know if i'd do both OG 11 and OG 12.. that seems like overkill. i'd pick one or the other. since you already have the manhattan SC guide, you should be able to register your book so you can get the 6 free CAT tests.

also, just because you 'completed' a book doesn't mean that you're done with it. if you take a practice test and find you're still getting sentence corrections wrong, for example, then that means you don't truly understand the concepts. if this is the case, focus on studying why you got questions wrong, rather than focusing on getting them all correct