Gather your course materials. Decide what information and ideas your course will cover and collect appropriate readings--anything you can send as an attachment is ideal, but you can send students to the bookstore prior to the course. Plan lessons, homework, papers and/or exams.
Create a course schedule. Decide how many weeks it will take to run the course and assign readings, homework, papers and tests and quizzes over this time span. Keep in mind how much work you can reasonably expect students to complete. If you are teaching your course through a university or community college program, the number of weeks designated to your course probably will be predetermined, so check the school's academic calendar first.
Send an email welcoming students to your course several days before it is slated to begin. Include in your email the course schedule, a course description and their first reading and homework assignment. Also provide your contact information, including a phone number. Some students might be more comfortable asking you questions over the phone than through the Internet.
Respond to questions within a day or two and reply to homework assignments and papers promptly as well. Because there's no classroom setting, your prompt response is partly what keeps the course going. If weeks lag without interaction from you, your students might feel like they are doing work without an audience.
Consider adding a listserv component to your e-course so students can respond to course-related questions and interact with each other. Also consider offering "office hours" when you'll be available via instant messenger or telephone. These additional features will make your e-course more dynamic.
Issue grades following your school's grading procedure. Request student feedback to get ideas on improving your e-course next semester.