Here are some excellent links to a variety of PowerPoint websites. These sites have some great articles on creating effective PowerPoints while avoiding the "bad" presentations. Take some time to look around. You might also want to google for "effective powerpoints," "avoiding bad powerpoints" and "ugly powerpoints" to name a few.

You can also find the PowerPoint I created on Avoiding PowerPoint Abuse. Feel free to use and change this presentation. Let me know what you think too.