Perhaps there are already adequate guidelines as well as resources regarding on line conflict and resolution, but one resource might be the Public Conversations Project in Cambridge which has all sorts of resources for better communications - they managed a six month online conversation with about 25 people with varying views on abortion. I am sure they could help as could many other such groups.
Frances Kissling, visiting scholar
Center for Bioethics, UPenn
202 368 3954
Ten years of conversation on abortion:
https://secure.wikimedia.org/wikipedia/en/w/index.php?title=Talk:Abortion&am...
Fred