Informal Logic

The Dark Side of Debate - A tongue-in-cheek tutorial on using logical fallacies to win arguments.
http://www.fallacies.info/

The Fallacy Files - Explains and gives examples of logical fallacies from the media and everyday life, with references to sources.
http://www.fallacyfiles.org/

Informal Logic - Article in the Stanford Encyclopaedia of Philosophy, by Leo Groarke.
http://plato.stanford.edu/entries/logic-informal/

Thinking Straight - A brief introduction to informal logic and argument.
http://www.freewebs.com/thinkingstraight/

The Nizkor Project: Fallacies - 42 informal logical fallacies explained by Dr. Michael C. Labossiere, including examples.
http://www.nizkor.org/features/fallacies/

What is a Fallacy? Understanding Defective Arguments - Describes and explains formal and informal fallacies.
http://atheism.about.com/od/logicalfallacies/a/overview.htm

SkepDic - Logic and Perception - Articles with many examples covering all variations of faulty thinking.
http://skepdic.com/tilogic.html

Logic and Fallacies - Atheism Web's guide to logic and fallacies in practical reasoning.
http://www.infidels.org/news/atheism/logic.html

PRIME: Fallacies - A short article on informal fallacies from the Platonic Realms Interactive Mathematics Encyclopedia.
http://www.mathacademy.com/pr/prime/articles/fallac/

Logical Fallacies and the Art of Debate - A guide to using logical fallacies in debate.
http://www.csun.edu/~dgw61315/fallacies.html

Logical Rudeness - Entertaining article by Peter Suber discussing the rationality of a certain kind of rhetorical blocking strategy.
http://www.earlham.edu/~peters/writing/rudeness.htm

Logic and Diagnostic - Article by Paul Tomassi discussing the application of logical reasoning in medical diagnostic. Appeared in Minerva.
http://www.ul.ie/~philos/vol3/gnostic.html

Informal Fallacies - Dr. Charles Ess, professor of philosophy and religion, explains and gives examples of logical fallacies.
http://www.drury.edu/ess/Logic/Informal/Overview.html

Logical Fallacies - Explanations and examples of common logical mistakes.
http://www.logicalfallacies.info/

Stoneforest - Critical Thinking - Offers an introduction to critical thinking whose main content is the description of fallacies, offering examples in daily life.
http://www.stoneforest.org/critical.html

Propaganda Critic - Discusses various propaganda techniques, provides contemporary examples of their use, and proposes strategies of mental self-defense.
http://www.propagandacritic.com/

The Power of Words - Emotional appeals, fallacies, manipulations, disinformation, misdirection, political correctness and the nature of truth. How some people get others to agree with their point of view, give them what they want, do what they ask and buy what they are selling.
http://www.aniota.com/~jwhite/words.html