Don't have a whole lot new to add, but I've been teaching for 4 years for the military with class sizes ranging from seven to 300.
- Biggest thing: know your material. If you know your content, you'll be able to speak to one person or a thousand with relative ease.
- Obviously choosing a topic you know about to begin with is great, but practicing it over and over again until it is basically memorized will help a ton.
- If you have to go for five minutes, shoot for six to seven when you're practicing. Your nerves will likely cause you to talk faster than usual and cut short your time on the day you're set to perform.
- Not much to say for getting over nerves...it just takes practice. It's like going up to a girl in the bar. Once you get over the fear of bombing (usually based on repeated success, or realizing that the world doesn't end if you do fail), the nerves will go away. Remember that nearly everyone in your class is going through the exact same thing you are. You're lucky in a sense, as you should have a sympathetic audience.
- As for the note cards - if you know your material you won't even use them. Have them there if it increases your confidence, but strive to not use them at all.
- Use humor to get the audiences attention and put them in your corner. I'm not sure if you're allowed to use visual aids, but short audio/video clips or funny pictures are a great way to get an audience engaged.
- Take a couple deep breaths before you start. After a minute, you'll get into a flow and the audience becomes secondary to the material.
- Try to be different from what everyone else is going to do. I'd bet you have a format you're supposed to follow, but most people giving their first speech are going to do "textbook" things like starting with a famous quote or some other cliche shit.
- Transitions are another place where you can really shine that most people just starting out absolutely SUCK at. Find something to link the topic you just talked about and the topic you're going to talk about next. Even a mechanical transition ("We just talked about xxx, now we're going to talk about yyy") will help your audience follow the pieces of your presentation. As you get more practiced, you can spice up your transitions like the example(s) on the previous page.
- Have fun - it's not going to be as bad as you'll build it up in your head.