A possible first step in offering an on-line subject might be to set up a subject web page. More material, additional leaning experiences and further support services could be added to the page as needs demand, and time, expertise and budgets allow.
Print is effective for large amounts of slow changing content.
Face to face may be best for engaged interaction. Using the Web in Teaching Locating, evaluating and using Web-based resources a self directed tutorial. Online resources for student research search techniques, advice on minimising and detecting plagiarism, and citation guides for online information.