An introduction to an essay is a fairly short paragraph, for it provides (1) a motivator and (2) the thesis only.
1. The motivator can be a general observation, a relevant quotation from another source, a quotation from the novel that relates to your thesis, or a question that is also relevant to the thesis. For instance, one quotation that is highly relevant to Farenheit 451 is one from Ray Bradbury himself:
You don't have to burn books to destroy a culture; just get people to stop reading them.
Or you may want to find Bradbury's words in which he explains why he wrote his novel. Evidently, he thought about the Nazi's burning of the books and was greatly disturbed.
(Find something to motivate, or entice your reader to continue reading your essay)
2. The thesis is stated at the last sentence of the paragraph. It is a general statement based upon your observations as you read the text; this general statment contains 3 opinions that you will prove in the body of the essay. For instance,
In Ray Bradbury's Farenheit 451, the banning of books becomes detrimental to the healthy balance of society (or some other reason because ____________,________________,and ___________________.