A couple of years ago I created 8 free videos for Microsoft's User Group Support Services on the subject of How To Give Great Presentations. These videos became unavailable when the UGSS site was replaced with Microsoft's Technical Communities. Well now they're back. You can download them from here. The 8 videos are:-

1. Introduction (6 minutes 23 seconds)
2. Choosing The Right Presentation (8 minutes 30 seconds)
3. How To Explain Absolutely Anything (8 minutes 51 seconds)
4. Planning Your Presentation (22 minutes 52 seconds)
5. Nervousness And How To Overcome It (13 minutes 7 seconds)
6. How To Give Great Demos (26 minutes 9 seconds)
7. Preparing Your Laptop (19 minutes 21 seconds)
8. Presenting Your Presentation (35 minutes 39 seconds)

In addition you can read the paper upon which the videos are based.