Hi Acidalia,
I too am giving my first presentation at the end of this month, to a room full of academics, but I'm presenting on a topic I know well. I think if you don't know the subject, far from hiding your blushes, it might make them deeper! If you know the topic well you can anticipate questions & look good with your answers.
Otherwise, PowerPoints with pictures are always a good idea - gives your audience something to look at - and is there any possibility of audience participation?
Good luck (up)
Mog