Can someone explain to me the three times throughout the novel that conflict arises when people are caught reading books?What are the three...

The first significant conflict surrounding a person and books is the woman who chose death over superficiality. She is unnamed, (the neighbor who turned her in is Mrs. Blake) but her action is a catalyst for change in Montag's thinking. The firemen throw her books from the attic and then fill the house with kerosene gas. While Montag pleads for the woman to leave, she strikes a single match and goes up in flames with her home and her books. That anyone would find books important enough to die for stuns Montag, and causes him to think again about his own life and about the humanity behind the books.

The second event is Montag's revelation of the books to Mildred. Montag is left unsettled by Beatty's visit and his discourse on books. He has a sense that he needs to do something, but he can't determine exactly what that something may be. He reveals, to Mildred's horror, his stash of books collected over time. The first line he actually reads is from Gulliver's Travels by Jonathan Swift, an interesting choice by Bradbury, as it is a political satire protesting the same ambivalence Bradbury decries in Fahrenheit 451. The result of this conflict is the increasing divide between Montag's thought and Mildred's superficiality.

The final event is Montag's poetry reading to Mildred's friends. He listens to their careless conversation about serious subjects (life, death, marriage, war, children...) and Montag's frustrated response is to bring a book of poetry to the parlor. He reads "Dover Beach" by Matthew Arnold. The simple beauty of the words and the depth of meaning in them brings Mrs. Phelps to tears, angers Mrs. Bowles, and frustrates Mildred. The end result of his poetry reading, however, is that it is the action that seals his fate. It is not long after this event that Montag pulls up in the Salamander to burn his own house.