The random thoughts of a sceptical activist.
For good introductions to argumentation, read the University of North Carolina’s Writing Center Handout and Argument on the Changing Minds website.
Logical fallacies are all too common in comments: the following websites describe several types of logical fallacy. Using any of these fallacies detracts from anything useful you may be trying to say and destroys what you are trying to say.
Fallacy – Wikipedia, the free encyclopedia
Logical Fallacies: The Fallacy Files
Top 20 Logical Fallacies – The Skeptics’ Guide to the Universe
Fallacies: The Nizkor Project