Argumentative essay paper?????

I was igned to write an argumentative paper on a philosopher's argument on a topic.I chose to do it on Aristotle and Socrates?How do i do an argumentative paper, do i just state why i agree or disagree on why i chose this person?I don't really know how to write an argumentative essay..any help would be appreciative and is doing on Socrates and Aristotle a good topic?