A good introduction for any essay should serve two purposes: provide a little background information on the subject of your paper, and introduce the reader to your thesis statement.

If you essay is about Shooting an Elephant, by George Orwell, you should mention this in your introduction. You may wish to give a little description of this piece, mentioning the themes of imperialism and conscience or guilt. 

If your essay is not about George Orwell's work, and is otherwise titled Shooting an Elephant, tell your reader a little bit about what they will read in the coming paragraphs. Think of the introduction as a "short and sweet" description of what will be in the rest of your paper.

When it comes to your thesis statement, this may be one or a few sentences which summarize the "message" of your paper. If you are writing on George Orwell's essay, consider the following questions. Did you like Shooting an Elephant? Do you think it made a good point? Why or why not? Did you learn anything from the essay?

It may be easiest to write your introduction after completing the body of your paper. This way, you could read over what you already have written and think about what information in your paper is most important.