The document provides five rules for presenting code in slides: 1) Use a monospaced font for readability, 2) Use large fonts that are visible from the back of the room, 3) Only highlight syntax where needed to avoid walls of text, 4) Use ellipses (...) to remove unnecessary code, and 5) Add annotations to draw attention to specific parts of the code. It then demonstrates these rules by presenting an example of using promises in JavaScript to avoid nested callbacks.