Things to consider when giving presentations:

Eye contact.

Your presentation will be much more interesting if you look at your audience. Don't look down at your feet. Try not to look at your notes or at the screen too often: you will lose eye contact.

Body language.

Use your hands to clarify your meaning. Don't put your hands in your pockets. Posture and gestures. Don't make distracting gestures like scratching your head or fiddling with your pen.

Voice projection:

Don't whisper. Speak loud enough so the people at the back of the room can hear you.

Intonation.

Remember in English-speaking people vary the tone of their voice a lot in order to show their interest and feelings. If your voice is flat, your presentation will sound boring and your audience will fall asleep.

Don't read your notes aloud.

You can use notes to remind yourself what to say next, but only as a guide.

(The next part is for if you are planning to use some technology in your presentation.)

Don't spend hours demonstrating a web site.

Just show a few relevant parts. Remember, you may have to wait for pages to download.

Be prepared for technical problems.

If you are using the Internet, be prepared to say something while your page downloads. If the site crashes, give your presentation without it. Don't depend 100% on the Internet.

Using PowerPoint.

The PowerPoint text should support what you are saying, but not replace it. Dont read aloud from your PowerPoint. It should provide brief notes and possibly images to clarify your message. However, PowerPoint is an excellent tool for presentations.

Good luck with your presentations!