All of the above, and...
Don't assume that the student knows something, even if it seems very basic to you.
Don't encourage sloppy habits, but do be encouraging of the student's efforts - sometimes hard to do both at once.
Prepare some good handouts. Students can't absorb everything in class and will appreciate having something at home to refer to.
Tell the students about local guilds and quilt shows to fuel their new quilting habit.
Recommend some good books on basic quilting, and if possible bring your copies with you so the students can look through them during class.
You will probably have one student who is (pick one type) know-it-all/down-in-the-dumps/talkative/grumpy/unprepared. Try to keep that person from ruining the class for everyone else.
Good luck with your teaching. Quilt classes are almost always fun, and sometimes what you learn isn't exactly what you came to learn, but it still counts.