There are a few basics that are essential to being a good GSI. Different people will phrase these slightly differently, but here's the general consensus:
You CANNOT be a good GSI if you are not attending the course lectures regularly. Even if you think you know the material well, different professors explain material in different ways, and emphasize/de-emphasize certain material. In order to be able to field student questions and present a coherent course structure to students in section, you must know what happened in lecture (sometimes including mistakes made by your professor, which you should be prepared to correct).
Many professors will tell you that lecture attendance is not required; I am telling you that it's highly, highly encouraged.
However, you're not expected to attend every lecture, especially when you have other important commitments, but a few hours a week is a fairly small time investment and you can always work on other things if necessary during the lecture.
In addition, you may find it useful to skim the assigned reading for the class you're teaching. Similar to going to lectures, even if you think you know the material, the book might explain things in a different way or use different analogies or examples. Many students won't do the reading, but many will and they will sometimes have very specific questions from the reading.
You must come into section with a plan. “Winging it” will not work. The best sections happen when the GSI has clearly laid out, step by step, what they want to accomplish before getting to the classroom. This doesn't necessarily mean you need a fully drafted lesson plan each week, but having some notes on the order in which you're going to do things is quite useful. Things to do beforehand include (but aren't limited to):
Furthermore, the worksheet is arguably the most important part of section. It is essential that the students have a clearly written, hard copy of what you're asking them to do; simply telling them what to do won't work. Coming up with your own good worksheet generally takes less than an hour, especially if you borrow from other GSI's worksheets (found in the electronic Big Red Binder).
People work hard for bosses they like and don't work hard for bosses they hate. For this reason, it is essential that you develop good rapport with your students. With only one hour of section per week, this task is very difficult. A good starting point, however, is to learn your students' names immediately (within the first week or two of section). I know this is tough, but trust that you will be rewarded for your efforts.
Some ways to learn students' names are:
central@astro
well in advance of your section to let them know that you'd like to use the camera. This should be a last resort, I feel.Set aside a few hours each week to help students outside of class. (Your course head will almost certainly require you to do this to some extent via office hours and TALC duties.) Many undergraduates are intimidated by professors but are more willing to talk to GSIs. For the shyest students, you are the only source of personal help for the course. It is therefore imperative that you make yourself as approachable and available to students as possible. Generally 1-2 hours of scheduled office hours plus one night of TALC per week is plenty.
You should announce your office hours, either unilaterally or after polling your students on times/days they'd prefer, as early as possible, preferably during your first section. You should also remind your students that they are welcome, nay, encouraged to make an appointment to see you outside of your scheduled office hours, if they so desire. (With even a moderately large section, at least some of your students will likely have conflicts with your scheduled office hours and be unable to attend them even if they really want to.) Remember that if you're teaching freshmen some of them may not quite know what office hours are! Feel free to take a moment and explain this concept to them. Many won't need this, but you don't want to leave those few that do hanging out to dry.
I am certainly here to help you and give you advice if (and when) you need it; that's the point of Ay 300! However, I'm not your only line of defense. Your Head GSI is a great person to talk to if any issues should arise. Part of his/her job is to make sure that all of their GSIs (including you) are doing well and that all sections in the course are running smoothly. Also, don't hesitate to talk to other astro grads; they've pretty much all taught before and no matter how old and creepy they might seem, they were once new GSIs too! Finally, there's always the professor of your course that you could talk to, but be forewarned, profs can sometimes be tough to get a hold of during the semester and, because they tend to be in less direct contact with their students, may have a less-than-accurate perception of what's going on.