I am going to respectfully disagree with Pelihu. I don't think Strunk & White will help much.
Your verbal is lacking quite a bit. The easiest way to improve your verbal score is to work on your sentence corrections. I suggest using a regular prep book such as Princeton Review. The stuff in there is pretty easy. Then you might want to move on to
Manhattan Gmat's sentence correction.
hint: Learn the idioms in the context of a sentence, not just as a fragmented phrase!!!
Forget about dense material, forget LSAT CR or RC. You need to crawl before you can walk. Try getting into the mid 30s for verbal before you think of the 40s. As for reading comprehension, start reading the New York Times or The Economist. Read it and be able to comprehend it to the point of having a meanignful conversation with someone else. No offense, that might be beyond you right now.
Baby steps. You're not going to go from a sub-30 to a 40. There are native English speakers who can't hit 40.