Hi Vamshimedum,
Your quant score seems to be solid.
Now onto your verbal. I am not expert and I am currently still studying for the gmat, however from my experience bringing a verbal score from 20 - 30 is a lot easier then say 35-40.
So what should you do?
(1) Take a couple (or 3) practice CATS, find the free ones (mgmat, veritas, mba.com etc) or buy a set.
(2) Figure out what in verbal is going wrong, for me it was SC, but you may have to tweak everything.
Figure out what your weakest area is, then start focussing on that.
If your problem is SC... you MUST MUST MUST go with E-GMAT, it is by far the best tool for SC. Your confidence will shoot through the roof!
Another very helpful book is MGMAT SC, however, it may be a little intimidating, as it uses quite a few fancy terms.
I used both, and they do go hand in hand, but I would reccommend going with E-GMAT.
I didnt buy any books on CR or RC, but I hear good things about Powerscore CR bible. I know E-GMAT also does CR, but I cant comment on this.
As for RC, my strategy is simple:
Read and take notes. Thats it! Try not to spend too much time on reading, tops 5 minutes, but make sure you write stuff down, sometimes it means I write the entire topic sentence down of a new paragraph! Just to make sure you dont get lost.
Bottom line:
SC help = E-GMAT
CR help = do some research, Powerscore is suppose to be good
RC help = practice till u drop, no matter what day, or how tired I am, I read 2 RC passages EVERYDAY, from watever source i find.
Hope this helps.
