You won't need a prepared text or extensive notes. If you do, it indicates that you didn't practice enough, or else you're not the expert you previously thought. You can use an outline to ensure coverage of key points or to better organize your thoughts, but keep it at the podium or some other discrete place. Don't refer to it constantly, but only when you reach the end of a particular segment, to check that you mentioned everything planned, and to remind you of the next segment.
The structure of your presentation is important to your message. Unless you have a lot of presentation experience, stick to the basics. Tell the audience what you're going to say, say it, and then sum up what you said. But don't begin this process without first warming up the audience. Its members will respond better if you treat them as personally as possible. If you don't know anyone, find out something about them and why they came. Ask questions and wait for a response.
This makes people feel more relaxed and comfortable, while also giving you valuable information about how to deliver your talk. You might find that the group has a different perspective on the subject matter, or has less experience than you had originally thought. This provides one last opportunity for you to adjust the level or perspective of your presentation to deliver the most benefit to your audience.
Your visual aids should enhance your message. Software technology keeps raising the bar on the definition of an acceptable presentation. Twenty years ago, typed slides on an overhead projector were state-of-the-art visual aids. Now it's possible to use Microsoft PowerPoint to create a full multimedia presentation with graphics, video, audio, and animation. The problem with the availability of technology is that many use it to disguise inexperience at giving presentations. Also, some of us prefer playing with technology to motivating our audience. The rule of thumb: don't use a graphic, animation, or other multimedia feature unless it clearly contributes to the audience's understanding of your topic.
Learning Goes Both Ways
Don't try to appear as an expert on any topic unless you're widely recognized as such an expert. This is one of the most difficult attitudes for a novice presenter to maintain, because it justifies why you're in front of the room. It destroys your credibility, though, if you make mistakes that members of the audience can readily identify. Take the opportunity to learn from them while they're learning from you. A presentation is rarely a one-way street.
When I taught college computer science, at least one adult student in any class possessed extensive work experience in some aspect of the course. They were probably better than I was in that area. For these students, I tried to put the subject into a larger perspective so they could integrate their practical experience into the theoretical framework.
I've left for last the most obvious barrier to good public speaking—simply the fear of speaking in front of a group. The best way to overcome this fear is to practice. Work on your presentation style in front of a mirror. Ask your spouse to videotape you, and then work together to critique the videotape. It can be a frustrating and embarrassing process, but it works well.
Join a speaker's bureau, toastmaster's club, or other company or community organization where people assist one another in public speaking. Volunteer to speak at clubs, schools, or events where the pressure is relatively low and you can practice. Ask a local college to allow you to guest lecture in the classroom or conduct informal workshops. You may even find colleagues who moonlight as night school professors; ask them.
Finally, watch good public speakers and observe how they keep their audiences engaged. They might tell jokes, relate personal experiences, augment their words with gestures and movements, or ask questions of their audiences. Pay less attention to what they say, and focus on how the audience reacts to their behavior. With practice, the best methods will come to you naturally.
I overcame my fear of public speaking when I realized the most suitable presentation style for me was one in which I converse with my audience. Most of us are capable of individual conversations without any problems, so I imagine that I'm talking with someone in the audience. This relaxes me and grants me a greater level of interaction with my audience.
With a good level of preparation and by feeling at ease in front of a group, you'll find that you're actually giving a performance. You're briefly in charge of the room, and with that comes both a responsibility and an opportunity. I once had a college professor who informed my class, "I'm not going to teach you anything. I'm going to get you excited about the subject so that you'll go off and learn it on your own."
If you follow this guideline, you may end up giving your audience less hard information, but you'll leave it better equipped to understand and share your point of view.