You might want to think of an informative speech as a speech to educate your audience. Start by thinking about a topic you find interesting, a topic you know a great deal about. Now, think about three to five important points you want your audience to learn about that topic. Those will be the "body" of your outline for your speech. Each of those talking points will need to be developed with details and examples. Once you have your talking points fully fleshed out, all you need to do is add an introduction and conclusion. Your introduction should give your audience a preview of your topic and your talking points, and your conclusion should remind your audience what points you just made. The structure of a speech is no different from the structure of an essay. The biggest differences are your audience, which is there, and that you are working from an outline with talking points, rather than reading aloud an essay you have written.