I’m assuming this is for a teaching position? My post is going to be based on this assumption.
It goes without saying to get there on time. I had an interview for an adjunct position last year, and showed up to the interview and an hour and a half late. Why? Because I got lost. My car’s AC was not working and it was 90 degrees and I was desparately lost. When I finally showed up to the building, I was bathed in sweat, my hair had turned into the wildest afro because of the humidity, and my eyes were red because I had been crying. Also, my foot was bleeding because I hadn’t broken in my shoes yet. (And yet I magically got the position!)
So find the place the night before and get there early, to beat the traffic and handle parking.
I’m assuming the presentation will be for a general audience, both students and faculty? My advice would be not to try to wow everyone with your technical expertise. Last year, I had to sit through about five candidate presentations, and only one was memorable in a good way. The others either put me to sleep or made me feel mentally retarded. The presentation should reflect your teaching abilities as well as your research. Don’t assume everyone knows the words you’re using. Do not use abbreviations without defining them first.
And make sure all figures are clear and uncluttered. There is nothing more intimidating than having a hundred figures thrown at you in rapid fire with someone saying, “As you can see…” Half the room will feel stupid and the other half will think you’re stupid.
If it’s an hour long presentation, make it 50 minutes. Do not do one of those exhaustive talks that includes everything you’ve ever done in your research career. Even if everything is interesting, you will wear everyone out and no one will know what questions to ask you afterwards (which is what you want them to do).
Be personable during the presentation. Do not stand with your arms crossed (especially when you’re answering questions). Sprinkle in humor. Do not do the cutesy “I’m so nervous!” thing at the beginning of your talk, because everyone already knows you’re nervous. No need to emphasis it.
Your interview process will probably involve meeting with a list of people in the department, including graduate students. Try to find out what everyone does beforehand. Be friendly and warm to the grad students. I always liked it when candidates bothered to ask about our research interests and what kinds of classes we wanted to see being taught. We didn’t have a major role in the decision-making process, but our opinions were often sought in the “iffy” cases. I once gave the thumbs-down on a candidate who made an uncomfortable lunch companion. She just sat there with her nose in the air, not asking questions and barely answering the ones we asked her. So make sure you’re enthusiasm and curiousity shines through.