I suck at Verbal and Reading Comp too....the bad news is...you can't do anything about reading...if you didn't read a lot as a child then its going to take years to be a fast reader...
Verbal...the only thing you can do is memorize all the vocab words in the Kaplan book (I have the book from the actual course) and hope they are on the real exam!
It depends on how long you have to prepare for the PCAT. If you have quite some time, you can read a bunch of science articles daily (from www.sciencedaily.com). Or, you can subscribe to a Science Magazine.
You should do as many practice problems as possible, from the Kaplan Book, or from the Examkrackers Reading Comprehension Book(for the MCAT).
For verbal, it might help to learn the roots, prefixes, and suffixes of the English Language...from that you can get a sense of what the word means. Also, you can learn some verbs in a Latin-based language, as a lot of complicated english words are based on these simple verbs in the other language. You can also try reading 18th to 19th century literature, and making a list of words that you don't know...and then try defining them. Doing the last one requires time, but you can do all other things, even in a short amount of time.
People say to read science articles and stuff to help you on the reading section. For that to do any good you'd probably have to read hundreds of those stupid things. A far better use of your time is mastering the bio and chem sections which can be studied for and will offset a bad reading or vocab score. I got a 52 on the verbal section. Non of the words used in part of that section are used in the common english vocabulary and I really think this section should be slightly changed. But I did do well in the bio section (96). With those two being the high and low and the rest being in the middle of those two I ended up with an 80 composite. Not amazing but supposedly its 'good enough'. If I have to take it again if I don't get in this year I will try to memorize more words from my vocab builder book and again study hard for bio, chem, and a little math.