This depends on what you are trying to prove about Fahrenheit 451. Being a work that demonstrates that man should value the ability to think for himself, or that the government should never have total control, I suggest you pick a message (of the two I mentioned) to begin. Then, think about how the author gets that message to the audience.
I encourage my students to TAG their thesis statements. This means to use the title, author and genre. Then come up with a strong verb like demonstrates, expresses, delineates, or portrays. Finally describe the message you think you see.
When you get to topic sentences for writing about a piece of literature, you might mention in each topic sentence a different strategy the author uses to get his message across to an audience. In this case, this novel happens to be a dystopia and that fact drives home many points... you write those points. Another paragraph might be about character. Another one might be about plot.