Students enrol and then take part in discussions by writing answers to questions. These answers are published on a particular site. Other students on the course can read the answers before they respond to the points in the discussion. And, of course, the tutors chip in. I cannot here, go into how to set up response forms.
Details are readily available in the books mentioned above.
However, to receive the responses, you can do one of two things. Simple Method Set up the form so that any response is emailed back to you. This method is quick and within the possibilities of anyone who has worked through the above books. However, sending your form response via email is a security risk. Still, it is better than having no responses.