I haven’t taught online yet, but there are several options out there. I’m doing my Master’s degree online through the University of Phoenix, and their program is great. Here’s how it works from a teacher’s perspective. It’s university level, and I don’t know if you need different qualifications than teaching at public schools, but here goes.
Courses run for six weeks, usually. The professor posts links to course materials online, and generally posts a lecture each week. The professor also posts about five discussion questions per week for the students to discuss. Students read the course materials and the lecture, and respond to the discussion questions on a forum like this one at CAF. The professor also assigns group and individual assignments, usually one of either type per week. There’s lots of collaborative learning at UOPhx.
As a prof, I think you’re expected to spend about 15 to 20 hours per course per week, so most profs just teach one at a time. They write lectures, respond to discussion questions, grade papers and group projects, give feedback, and post links to other course materials. I’m pretty sure the computer keeps track of things like attendance and whether the assignments and questions are submitted on time, so the teacher doesn’t need to worry about that. And from what I’ve seen, the students are willing to lynch the teacher if feedback isn’t given within 7 days of the assignment being handed in. Also, from what I’ve seen, most profs spend more than the minimum 15 hours online each week. Like all teaching jobs, the number of hours they say you work is way less than the number of hours you really work.
Anyway, I don’t know much about teaching public school courses online, but that’s what I know about teaching adults. Good luck!