be as prepared as you can be....do what mr listener said and look at the wall behind everyone...not into their faces...keep good notes with wide spaces in between lines, so you don't lose your place when speaking..and BREATHE....
Remember...you are the one delivering the information...you were chosen, not just stuck there to fill space...its a priviledge and consider it as such.

You will be fine...

Grant me the senility to forget the people I never liked,the good fortune to run into the ones I do,and the eyesight to tell the difference.