I would caution against simply reading (especially fiction) to prep for the GMAT Verbal.
I've been an avid reader of fiction for most of my life and yet when I got into the nuts and bolts of the Verbal stuff I discovered all sorts of weird rules and grammar nuances that they typically do NOT teach you in school and are not necessarily present or obvious in written works.
I personally studied the rules and patterns that applied to the Verbal Qs. I found "things to look for" and "rules of thumb" and learned how to immediately eliminate certain phrasings. I learned what the GMAT was looking for in reading comprehension. A lot of the grammar rules don't even apply to our everyday manner of speaking or writing. I'm sure I've violated 6 rules already in typing this, yet you all can (hopefully) understand me.
For someone with English as a second language, it might be easier to deconstruct the wording rules and patterns. Simply reading will probably help you with reading comprehension (and for understanding the QUESTIONS as well). but do not bank on it.
Hope this helps!