The Inter-University Consortium for Social and Political Research (ICPSR) at the University of Michigan is the largest archive for political and social datasets in the United States. Notre Dame is a member of this consortium so that you can access any of these datasets free of charge. http://www.icpsr.umich.edu/

The Council of European Social Science Data Archives (CESSDA) "promotes the acquisition, archiving and distribution of electronic data for social science teaching and research in development of new organisations in sympathy with its aims."  Its webpage links to 14 ICPSR-like data archives (including ICPSR) in the U.S. and Canada, 21 in Europe, and 5 others in Australia, New Zealand, South Africa, Israel, and Uruguay. http://www.nsd.uib.no/cessda/europe.html

The UCSD Social Science Data Center's "Social Science Data on the Internet" page allows one to search or browse a listing of 748 Internet sites of Social Science statistical data, data catalogs, data libraries, social science gateways, addresses, and more. http://odwin.ucsd.edu/idata/

The University of Michigan has compiled a page with approximately 80 links to important or unusual datasets useful to comparativists.  http://polisci.lsa.umich.edu/grad/comparative/data.htm

Paul Hensel's International Relations datasite: http://garnet.acns.fsu.edu/~phensel/data.html. This is probably the most comprehensive guide to data useful for International Relations and Comparative Politics.

Richard Tucker, an international relations specialist at Vanderbilt, has compiled a "Replication Data Sets Archive" that links to many datasets used in publications. Many of these would be useful for research in comparative politics or international relations. http://www.vanderbilt.edu/~rtucker/methods/replication/ [Temporarily off line]

Michael Coppedge's data on democracy and Latin American party systems

NationMaster has an easy interface for all kinds of data about most countries, and it also is useful for producing color-coded maps. However, downloading usable files of data requires a fee.

The Laboratory for Social Research at Notre Dame archives a few hundred datasets. You can access them from any computer with a K:\ drive or by going to the LSR offices on the 9th floor of Flanner Hall. There are consultants there who can help you. The best person to contact first is Mary Lee (Lee.82@nd.edu). A list of their holdings is at http://www.nd.edu/~lsrweb/.

Hesburgh Library at Notre Dame provides access to a few datasets, including World Development Indicators and Polling the Nations, through its webpage: http://lib.nd.edu/eresources/gateway/subjects/political_science-Alldb.html.