General Introductory books available for free on the Internet
Henry Hazlitt, Economics in One Lesson (very easy)
Frederic Bastiat - Selected Essays on Political Economy (very easy)
in particular the essay What is Seen and What is Unseen and The Law
Friedrich Hayek - The Use of Knowledge in Society (requires some knowledge of economics but essential)
Israel Kirzner - The Economic Point of View (some knowledge of economics helps but not technical)
Leonard Read - I Pencil (very easy)
Jean Baptiste Say - A Treatise on Political Economy (full treaty accessible to everyone)
Adam Smith - Wealth of Nations (full treaty, you might wish to read some parts if not the whole thing)
Stroup and Gwartney - What everyone should know about economics and prosperity (easy introduction)
Henri Lepage, Tomorrow Capitalism (easy introduction)
Gwartney, Stroup and Lee - Common Sense Economics (full website with teacher and student resources)
Gwartney, Stroup and Lee - Common Sense Economics (a version of the book is downloadable here)
And a few very good ones that are not free
A Few Classics of Classical Liberalism
Bastiat, Frédéric (1845/1996) Economic Sophisms, Published: Irvington-on-Hudson, NY: The Foundation for Economic Education, Inc., trans. and ed. Arthur Goddard.
Bastiat, Frédéric (1848/1995) Selected Essays on Political Economy, Published: Irvington-on-Hudson, NY: The Foundation for Economic Education, Inc., trans. Seymour Cain, ed. George B. de Huszar.
Hayek, F.A. (1960), The Constitution of Liberty, The University Press of Chicago, Chicago
De Jasay, Anthony (1985) The State, New York, Oxford University Press
Hayek, F.A. (1973) Law, Legislation and Liberty, vol 1. Rules and Order. Routledge & Kegan Paul, London and Henley.
Hayek, F.A. (1976) Law, Legislation and Liberty, vol 2. The Mirage of Social Justice. Routledge & Kegan Paul, London and Henley.
Norberg, Johan (2001) In Defense of Global Capitalism.
Say, Jean-Baptiste (1880) A Treatise on Political Economy: or the Production, Distribution and Consumption of Wealth. Translated by C.R. Prinsep and Clement C. Biddle. New York: Augustus M. Kelley.
Smith, Adam (1981), An Inquiry into the Nature and Causes of the Wealth of Nations, two Volumes, Oxford University Press, Liberty Fund. Edited by H. Campbell and A.S. Skinner.
Simon, Julian (1981) The Ultimate Resource
Kirzner, Israel M. (1978) Competition and Entrepreneurship, New York University Press
Demsetz, Harold (1967) Towards a Theory of property Rights, American Economic Review, May 1967
Coase, Ronald H. (1974) The Lighthouse in Economics, 357-376, The Journal of Law and Economics, Vol. XVII (2), October 1974
Menger, Carl (1976) Principles of Economics, New York University Press, New York and London.
Menger, Carl (1985/1883) Investigations into the Method of Social Sciences with Special Reference to Economics, New York University Press, New York and London
Hayek, F.A. (1945) The Use of Knowledge in Society, American Economic Review, Vol. 35, N°4, 519-30.
Hayek, F.A. (1978) Competition as a discovery Procedure, in Hayek, F.A. New Studies in Philosophy, Politics, Economics and the History of Ideas, The University of Chicago Press,
Buchanan, J. (1979) What Should Economists Do?, Liberty Fund: Indianapolis.
Rizzo, Mario J., ed. (1979)Time, Uncertainty and Disequilibrium: An Exploration of Austrian Themes, Lexington Books: Lexington, Ma. et Toronto.
Mises, Ludwig von (1949/1966), Human Action - A Treatise on Economics, 3ème édition révisée, Contemporary Book, Inc.: Chicago.
Mises, Ludwig von (1978), The Ultimate Foundation of Economic Science, Sheed Andrews and McMeel Inc.: Missian, Ka.
O'Driscoll Jr., Gerald P. and Mario J. Rizzo (1985) The Economics of Time and Ignorance, with a contribution from Roger W. Garrison, Basil Blackwell: Oxford et New York.
Kirzner, Israel M. (1979) Perception, Opportunity and Profit - Studies in the Theory of Entrepreneurship, The University of Chicago Press: Chicago et Londres.
Kirzner, Israel M. (2005) Concurrence et Esprit d’Entreprise, Economica 2005
Kirzner, Israel M. (1979) The Perils of Regulation: A Market Process Approach in Discovery and the Capitalist Process, The University of Chicago Press: Chicago and London, 1985. 119-140
Eamonn Butler (2011) Austrian economics: A primer, Institute for Economic Affairs
Bauer, Peter (2002) Disregard for Reality in, David Boaz ed. Toward Liberty: The Idea That is Changing the World, Cato Institute: Washington D.C., 38-54.
Bhagwati, Jagdish (2002) Free Trade Today, Princeton University Press
Easterley, William (2001) The Elusive Quest for Growth, MIT Press: Cambridge, Ma. and London, England.
Barnett, Randy (1988) The Structure of Liberty: Justice and the Rule of Law, Oxford University Clarendon Press
Benson, Bruce L. (1990) The Enterprise of Law, Pacific Research Institute
Berman, Harold J. (1983) Law and Revolution: The Formation of the Western Legal Tradition, Cambridge, MA, Harvard University Press
Den Uyl, Douglas and Rasmussen, Douglas (2005) Norms of Liberty, Pennsylvania State University
Epstein, Richard A. (1995) Simple Rules for a Complex World, Harvard University Press
Leoni, Bruno (1991) Freedom and the Law, Indianapolis, IN, Liberty Press
Baechler, Jean (1976) The Origins of Capitalism (English translation), New York, St. Martin's Press
Baechler, Jean (1971) Les Origines du capitalisme, Paris, Gallimard
De Roover, Raymond (1976) Business, Banking and Economic Thought in Late Medieval and Early Modern Europe, Chicago, University of Chicago Press
De Roover, Raymond (1958) The Story of the Alberti Company of Florence, 1302-1348, as Revealed in Its Account Books, Harvard Business Review 32 (Spring 1958) pp. 14-59.
Landes, David (1998) Wealth and Poverty of Nations Why Are Some So Rich and Others So Poor? New York: W.W. Norton
Milgrom, Paul; North, Douglass C. and Weingast, Barry R. (1990) The Role of Institutions in the Revival of Trade: The Law Merchant, Private Judges, and the Campagne Fairs," March 1990 Economics and Politics 2 (Blackwell), pp. 1-23;
Daniel Klein (1997) Reputation: Studies in the Voluntary Elicitation of Good Conduct, Economics, Cognition, and Society Series, Timur Kuran, ed., Ann Arbor, MI, University of Michigan Press
North, Douglas and Robert Thomas (1973) The Rise of the Western World: A new economic history. Cambridge University Press
Pipes, Richard (1999) Property and Freedom, Vintage Book
Pirenne, Henri (1956) Medieval Cities: Their Origins and the Revival of Trade, Princeton, N. J., Princeton University Press
Deirdre McCloskey (2006) The Bourgeois Virtues, University of Chicago Press
Deirdre McCloskey (2010) The Bourgeois Dignity, University of Chicago Press
Deirdre McCloskey (2016) The Bourgeois Equality, University of Chicago Press
History of Economic Thought
Chafuen, Alejandro (1986) Christians for Freedom: Late Scholastic Economics, Ignatius Press
Rothbard, Murray N. (1995) Economic Thought before Adam Smith, Volume 1, Edward Elgar
Grice-Hutchinson, Marjorie (1978) Economic Thought in Spain, Edward Elgar
Némo, Philippe (2013) Histoire des idées politiques, Presses Universitaires de France
Hirschman, Albert O. (1970) Exit, Voice and Loyalty Harvard University Press, Cambridge, MA.
Niskanen, William (1971) Bureaucracy and representative government
Olson, Mancur (1965) The Logic of Collective Action: Public Goods and the theory of Goods, Harvard University Press
Tullock, Gordon (1978) Le marché politique: analyse économique des processus politiques, Economica
Tullock, Gordon (1976) The Vote Motive, Institute of Economic Affairs