What are examples of irony in part one of Fahrenheit 451?

The main irony is Part I of Ray Bradbury's science fiction novel Fahrenheit 451 lies in its premise.  The opening sentence of Bradbury's novel reads: "IT WAS A PLEASURE TO BURN."  That the reader will soon be introduced to the story's protagonist, Guy Montag, and Montag's profession, firefighter, is supremely ironic. That opening sentence is immediately followed by this passage:

"IT was a special pleasure to see things eaten, to see things blackened and changed. With the brass nozzle in his fists, with this great python spitting its venomous kerosene upon the world, the blood pounded in his head, and his hands were the hands of some amazing conductor playing all the symphonies of blazing and burning to bring down the tatters and charcoal ruins of history."

We still do not yet understand the precise meaning of these descriptions. Bradbury's opening suggests the ravings of a pyromaniac, a deranged psychopath against whom brave firefighters will have to contend.  That these thoughts are the product of the mind of a firefighter, and of his colleagues, and that these thoughts will be revealed as official government policy, lends Fahrenheit 451 an irony that places his novel among the most important in the history of the genre.  

Another bit of irony involves Montag's new friend, Clarisse McClellan, the seventeen-year-old teenager who befriends him and who will come to represent a window through which Montag can begin to view an alternate and infinitely more humane reality.  Early in Part I, when Clarisse introduces herself to Montag, and noting his profession, she states, "So many people are. Afraid of firemen, I mean. But you're just a man, after all..."  That people should be "afraid of firemen" is another example of irony, as people the world-over associate firemen in an extremely positive light.  It is the fire department to which we turn when our lives and possessions are threatened by fire.  In Bradbury's novel, as noted, the world has been turn upside down by an autocratic regime that fears the people over whom it rules, with books and the knowledge they contain the greatest threat to regime stability.