Rather than rehash all the basics here, I recommend you read some
foundation material on libertarian principles so you can ask more
specific and more informed questions. Start with David Friedman's
_The Machinery of Freedom_, or _Hidden Order_. I'm sure others
here will have similar recommended works. Friedman has lots of
stuff on his web site as well <http://www.best.com/%7Eddfr/>, but
much of it is more advanced.