4. What is Argument Mapping?
Argument Mapping is the expression of an argument is in a structured visual form.
Arguments have been expressed in prose since the time of Socrates.  Modern information technology has made little impact on the expression and understanding of arguments.  We now use word processing, electronic mail and spell checking instead of just the pen and paper but this has little changed the way arguments are understood.
Argument mapping allows you to move from prose to a visual structure expressing premises, reasons, objections, assumptions and general commentary.
Look at the Wikipedia entry for more detailed definition.  There are also some papers on the goreason site.
Some good example files can be found on the Philosophy Programme - University of Natal, Durban site. (Unfortunately some of the RE3 files resolve to error pages which Argumentative does handle politely)
An excellent tutorial exists on Austhink's site.
A tutorial series in PDF may be found at Jamel Ostwald's site on his Classes page.
Other Argument Mapping software packages exist with Rationale being the best, in my opinion.  Other software may be found by looking at the Wikipedia entry.  They also have an excellent wiki.
There is an Argument Map group on Yahoo Groups here .