listen to what other people have had to say (i'd definately add the economist as a great pracitice reading source)...
but the best way to get good at VR is to read a lot. like a ton. and that means reading what you like. people may disagree, but in my opinion, it doesn't matter if its sci-fi or tom clancy or even romance (no exp there, but i'll assume this idea holds), if you can get to the point where reading and doing all that fancy mcat mumbo jumbo is just natural for what you like to read, then it'll fall into place on the real exam with harder material (which you will have seen on the practice exams etc).
the best way to add points, however, to VR is by going over the practice exams (i used kaplans) and learn exactly what differences there are between the way you think (ie, the way you respond to such questions as what was the author's point etc) and the way the test makers think. i found i exaggerated an author's position sometimes becuase i'm used to seminar discussions where that can be useful. once i went through 5 exams and made up a two page cheat sheet of dos/donts for VR, i did very well.