Here’s a great one-page article listing excellent tips on giving presentations from the master, Edward Tufte.

Never apologize
Most people wouldn’t have noticed the issues for which you’re apologizing—and it just sounds lame.

Match your presentation to the level of The New York Times or Wall Street Journal
Audiences don’t suddenly become dumber when they sit down to hear you speak—no reason to
“dumb down” anything!

Audiences are precious: respect them
Be clear—not simpleminded.