Listen to Mike:
Once you complete the presentation you will want to leave a valuable take-home document so that those in your audience can re-live your presentation and recall the high points. This handout will also contain your current contact information.
One page should suffice, but depending on the amount of information delivered and shared, you can have as many pages as fits the need.
Here is a sample handout that you can use as soon as you add your personal contact information.