One way to go about this task would be to find a complete copy of the text online and then do a word search (CTRL-F) for the word "book." Interestingly enough, the words "censor" and "censorship" only occur twice in the novel. Such a search will bring up gems like these. In the following passage, Montag describes the process of burning books.
"You weren't hurting anyone, you were hurting only things! And since things really couldn't be hurt, since things felt nothing, and things don't scream or whimper, as this woman might begin to scream and cry out, there was nothing to tease your conscience later. You were simply cleaning up. Janitorial work, essentially."
Later, Montag's supervisor, Captian Beatty, explains how the role of firemen in society changed from people who put out fires to people who started fires:
"And so when houses were finally fireproofed completely, all over the world (you were correct in your assumption the other night) there was no longer need of firemen for the old purposes. They were given the new job, as custodians of our peace of mind, the focus of our understandable and rightful dread of being inferior; official censors, judges, and executors. That's you, Montag, and that's me."
A few lines later, Beatty explains that one of the reasons for the censorship of books was to prevent people from being unhappy. Some books, Beatty argues, make people upset. We certainly wouldn't want a book to upset anyone, so therefore the book should be burned:
"Coloured people don't like Little Black Sambo. Burn it. White people don't feel good about Uncle Tom's Cabin. Burn it. Someone's written a book on tobacco and cancer of the lungs? The cigarette people are weeping? Burn the book. Serenity, Montag. Peace, Montag."