Imagine every single person in the audience is naked. Look everyone in the eye at some point during your ppt Don't mutter or mumble or rush Understand that actually, everyone wants you to be good Know that everyone is on your side. Prepare, prepare prepare practise, practise, practise
To add to Twitterqueen's advice - practice out loud. Wasn't until I was in full flow that I realised I had the phrase "master baker" which had to be uttered on stage in front of 300 people. Cats make a good audience for your practices. Good luck
Rule of three - tell them what you're going to tell them (introduction), tell them (presentation), then tell them what you've just told them (summary), and remember the majority of the time they're there because they want and/or need to hear what you're presenting, so you're not going into a hostile environment but a welcoming one.
Lots of practice! Much less stressful when you know you know your stuff. Don't be afraid to take comprehensive notes, better to risk being a bit rote than take a few bullet points and be nervous you'll go blank.
Also remember your body feels nerves and excitement very similarly: the shaking, tummy butterflies, the nervous poo beforehand, that feeling in your chest... they're all things we get when nervous OR excited! Some performers find it helps to say outloud 'I'm excited!' to reframe the nerves as something a little more positive.
Most of all, enjoy. It's nice having a captive audience hanging onto your every word! Enjoy the attention and being seen as someone who knows stuff.
And volunteer for more! I was terrified but had to do it weekly at one point in a new job and quickly grew to love and be proficient at it.
If you're easily put off and don't really want to look people in the eye, you can look just over someone's shoulder and it will appear as if you are looking at someone. Choose at least 3 points to look at - right, middle and left. Project your voice to the people furthest away. Don't put everything you're going to say on the slides (if you're using slides). You can tell the audience at the start whether you'll take questions during the presentation or at the end (if you're nervous, at the end is probably best). Good luck!
Have a killer attention grabbing opening sentence and practise practise practise it so you can nail it. Breathe, use pauses and speak really painfully slowly. Think about your body language and make it "match" what you are saying. Definitely remember the audience won't know if you skip a bit. Good luck
I've had to do these for audiences of 500+ in a past life. I convinced myself that everyone in the audience was on my side and none of them wanted me to fall over. I really don't think anyone in an audience wants that.
Practise, again and again, in front of a mirror out loud and TIME yourself. Be a couple of minutes shorter than your allotted time. Everyone wants to get the hell out of dodge and go for coffee break, no matter how good you are. They will love you for a shortened, even by a minute or two presentation.
If there is any possibility of introducing a bit of levity or humour into the presentation (and make sure it is a natural thing, yep tough I know), it will work wonders.
Other than that, being nervous is normal. Very normal indeed.