Unless you are working on a course of study under guidance, you probably won't go chapter by chapter. Indeed, you won't even read it linearly.
Once I finished my coursework, I tend to have a problem and go searching for material that may get me some traction on it. So a lot of keyword searches, a lot of reading prologues (prologues are where the author tends to give his conceptual overview of what the material in the book is for...I've learned a lot from reading random prologues in a math library).
Once I find something that looks interesting, I'm usually down to a few theorems or definitions that I think will give me traction. Then I start poking around the book or any other source I need/can find to figure out what I need to understand those definitions/theorems.
Usually at some point it becomes clear if they're a) irrelevant, or b) partially relevant. If (a), I drop the entire line right there and go back to searching. If (b), I start running counterexamples from the problem I'm working on against them, looking for where it breaks and seeing what I can salvage.
Prologues usually read like a novel, but occasionally stopping to look up words, so more like reading a novel in a foreign language. Once you're into the meat, your rate of progress is typically measured in hours per paragraph or days per page. But you probably only end up using ten or twenty pages out of a two hundred page book in this method.