It helps by establishing clear policies which you get people to accept prior to joining the discussion group. Typically, I would write a message to the offender offlist and explain that they might want to modify or reconsider their particular comments and try to settle it without adding to a public spectacle. If the offender continues, it is possible and I have opted to restrict their ability to post. That way they can still be on the list, but any message they post has to be approved by me before I pass it along to the list. At the very worst, I could simply remove them from the group, but this would be a very rare event.
Most people respond to the other methods.
The author will also discuss Web page authoring techniques and types of software to use. The intent of the presentation is to provide basic information for beginners or those considering whether to implement a Web site or whether to author Web pages on an existing site. Present a brief introduction about what is involved in establishing a Web site. Describe equipment and software needed to author Web pages. Share general principles and methods that my be useful to new Web page authors.