Hi gmat_buf.
If I had one advice, it would be NOT to use Kaplan CAT to practice or measure your progress!

With a "lowly" 620 on Kaplan, you might surprise yourself with a 700+ on GMATPrep1.
I strongly urge you to take GMATPrep1 right now (download for free from mba.com) and see how you're doing. From that point on, you can ask more detailed questions on what to study.
Verbal & Quant is good, but save that for a bit later.
Get OG11, it's worth it. It sorts the questions by difficulty level so you don't waste time with questions that are too hard or too easy. That would be the ONE resource I suggest right now.
Take the diagnostic test in the OG11 book, take the GMATPrep1, and identify which section you're the weakest on. Get
Manhattan books on that subject and practice problems in the OG/Quant/Verbal using
Manhattan books. Then come and talk if you run out of stuff to do.
Princeton Review strategies are good, but their questions don't help much. Same with Kaplan.
Good luck!