Here's an excerpt:
First, you have to get your audience’s attention. Once you’ve done that, you have to present your message in a clear, logical fashion–the beginning, then middle, then the ending. You have to deliver the information the way people absorb it, a bit at a time, a layer at a time, and in the proper sequence. If you don’t get their attention first, nothing that follows will register. If you tell too much too soon, you’ll overload them and they’ll give up. If you confuse them, they’ll ignore the message altogether.