Library of Economics and Liberty.
The site features free, full-text copies of books and essays of the classics in economics, a Concise Encyclopedia of Economics, links to the most commonly-used economics data bases, reading lists, featured columns and articles, and more.

Research Papers in Economics.
A collaborative effort of hundreds of volunteers in 63 countries to enhance the dissemination of research in economics. The heart of the project is a decentralized database of working papers, journal articles and software components. All RePEc material is freely available.

Resources for Economists (RFE).
From the Department of Economics, SUNY Oswego, this site lists more than 2,000 resources available on the Internet of interest to academic and practicing economists, and those interested in economics.