Please read the following sites while you are preparing for your debates. Knowing about fallacies is also very useful in all your academic writing. Watch for examples in advertising and from politicians.
"Fallacies are common errors in reasoning that will undermine the logic of your argument. Fallacies can be either illegitimate arguments or irrelevant points, and are often identified because they lack evidence that supports their claim. Avoid these common fallacies in your own arguments and watch for them in the arguments of others." A good website: http://owl.english.purdue.edu/owl/resource/659/03/

Here are some other good resources for understanding logical fallacies
http://www.onegoodmove.org/fallacy/toc.htm
http://jerz.setonhill.edu/writing/argument/fallacies.html
http://www.unc.edu/depts/wcweb/handouts/fallacies.html