Only a few organizations make a meaningful contribution to the understanding of free markets. 

This list includes just a few of the organizations that advocate for free markets free from intervention.

The Ludwig von Mises Institute
One of the primary sources for Austrian Economic Scholarship.
Foundation for Economic Education
"FEE’s mission is to inspire, educate and connect future leaders with the economic, ethical and legal principles of a free society."¬†One of the early advocates of Austrian economic education.
George Mason University: Economics
One of the only universities that supports free market economics.
The Center for the Advancement of Capitalism
Dedicated to advancing individual rights and economic freedom through Ayn Rand's philosophy of Objectivism. Not Austrian, but worth keeping in mind.