Hi Womiwom, I started my studies this last week. From what I've read on here, many of the posters with high scores suggest saving OG until the very end. Since those questions are so similar to what you'll find on the actual GMAT, it seems like a good idea to get the fundamentals down first. From what I've read, once you get the foundation, good strong questions are like gold. Once you've read them in the OG, they won't be quite the prep anymore, as you'd already seen them. I don't know if this is true, but I'll trust the experts on here.
Also, just like you, my math sucks. I'm shooting for admission in Fall, 2011 so we both have time, but our work cut out for us. It's amazing to discover just how much one can forget since school. For me, its been 13 years since my last college math course. I wish you all the luck and look forward to seeing your posts.