Hmmm, lots of ideas. I just googled "University of Maine" + photography. Most of what I found was at Augusta. Is that where you are going? If not, I think what I have to say would apply generally to other programs as well.
Their program has two options, either an associate degree in photography (usually these are 2 year programs and rather practically oriented) or photography as a part of the BA degree in art, at 200 and 300 levels, that is, second and third year, basically. I'm ignoring the color and photoshop courses. The Art degree offers a concentration in photography as one option, or lists the photography as options in the other concentrations (ceramic, painting, printmaking). I'm guessing that the class you would be addressing (if I have the right campus) would be the PHO 101/Art 235?
Have you been to the campus before? Do you know the professor well, or at all? Do you know the mix of students you may be working with? One thing that popped into my mind is that you mentioned that there would be 18 students, then later you said that the students would be 18+ years old. You may well be surprised to find some 50+ year old students. Also, you may find that some of the students have had little to no photo experience but some may have had a great deal. For example, one of my former students (1984 or so) from a two year commercial photo program went back to the U of Washington last year as a freshman, to emerge with a BA in art, concentrating in photography. She had worked as a professional photographer in the interim, for some twenty years.
Generally, university students are a bit more uniform than the students in community colleges, but in today's world, with changing careers, changing conditions in the job market, people disillusioned with their former boundaries, I would be very surprised if you could characterize the population of the room with any accuracy at all.
Also, those taking the course will have a variety of goals. A ceramics major, for example, may get a great deal more than s/he expects from the course, but the primary motive for signing up could well be to learn to photograph three dimensional materials for portfolio. There could be students from other disciplines in the class, as well (programs differ on this; UW does not allow non majors in the photo courses). You will also have students who are very interested in the subject and some who only need the credit. There may be one or two who think photography is an easy "A" since anyone can take pictures, and you may have someone who is taking photo to avoid having to take a drawing class.
The point is that a class is not monolithic. It is amazing how one class differs from all others. It's always a surprise. You will be dealing with a collection of individuals, about whom you can make very limited generalizations, so you can't assume that an approach that comes from a particular aesthetic orientation is going to fly.
I can tell you how I have thought of it when I bring people in as I did in January when I had to miss the first week of class. I wanted someone entertaining, enthusiastic, and who could bring interesting things to look at. I didn't expect him to actually teach content; only to provide something that could interest to a broad collection of individuals. I brought in a friend of mine with no particular academic credentials, one who is more an old time photographer than an "artist", who could come with lots of props. He brought, among other things, a twelve foot wooden tripod he built himself for his cirkut camera, and a wide variety of other cameras. He set up the cirkut and took a fake group portrait, 360°, without using film. He brought a bunch of cirkut prints, and a variety of other cameras. Big hit. Students told me that he must have made about ten trips out to his truck to bring all the stuff in.
You can't do what he did, most likely, and your aesthetic will show, no doubt. That's ok, because it's you. You will bring what you have, and it will be enough. In general, though, I'd suggest that it might best to avoid philosophical or aesthetic positions and keep it open. I'd try to let the audience drive the event. I very much like Ian's suggestion - be yourself. I'd suggest that you bring as much stuff to look at as you can. More prints, rather than less. Actual objects, rather than talk, will breath life into the event.
I think you can plan too much, and that won't be helpful. Your job is to provide a focus for them, something to stimulate their own thinking. I suspect that anything you bring, and your own story, would do that job just fine.
Next time I need someone to fill in for me, you can have the job, but be sure to bring Cardwell with you.
