Those who must present should read Eric Rescorla’s Some ways not to give a bad presentation. It’s short and gives you the essentials.
I would add to keep your bullet points short. And don’t orphan your bullets! I hate it when I see a bullet point on the screen and the presenter never connects the talk to the bullet.
And don’t shrink graphics (especially charts and graphs) down to meaningless blobs with unreadable text (and then apologize when you show it).
Once upon a time I wrote an anti-ppt manifesto for a class.
Edward Tufte doesn’t like PowerPoint either.
Powerpoint humor: check out Peter Norvig’s Gettysburg Address spoof.