Need help with your speech?
Also see: 5 Tips for a Great Wedding Speech
Besides bringing a smile to your audience, or causing them to feel inspired, the message is what matters. Know what you want them to know.
Relax. The audience is on your side. They are real people. Think of it as a conversation.
Then, practice some more. Learn where the periods and paragraph breaks are and allow them to slow you down. Say slowly any tricky words. Memorize passages so you can look directly at your audience for longer periods of time, as well as leave the podium. Remember the podium is a pivot, not an anchor.
If you botch a word, don't sweat it. Don't draw attention to it with a Ralph Kramden impression. "A homina homina homina," might bring a chuckle, but the audience will lose track of what you were saying.
If you can, arrive a day or two early and practice in an empty auditorium. Imagine an audience watching you. Go through your speech a few times. If you have props or a PowerPoint presentation, use them (or pretend you are using them). Speak loudly, assertively, just as you will on the day or your speech.