Visit Cogprints, an archive of open access papers in psychology, neuroscience, linguistics and as well as areas of computer science, philosophy, biology, medicine, anthropology other portions of the physical, social and mathematical sciences that pertain to the study of cognition.
The Inter-University Consortium for Political and Social Research (ICPSR)serves as an archival repository of datasets as well as a resource for training researchers in quantitative methods. Begun in 1962, ICPSR is the largest social science data archive in the world. Content consists of approximately 62,000 datasets and over 7,000 studies with half a million files. Subject areas covered range from social science topics such as economics and politics to sociological issues such as unemployment and drug abuse and include individual data files as well as links to fulltext content where available. This resource is a very good source of government data. The database offers assistance with exporting, citing sources and receiving data from researchers who wish to share their findings.
One special feature of ICPSR is its partner & projects page, listing websites dedicated to particular topics and areas of study on a variety of social issues (for example, minorities, aging, voting behavior). Subject matter focuses largely on underrepresented groups.