This guide provides information about locating datasets for use in the social sciences (with a bit about data in the humanities and big data in STEM fields). It also has resources on using datasets (including in teaching) and associated issues.
"This Web page features data collected by Carl Klarner of Indiana State University for public use and is supported by the Indiana State University Center for Governmental Services. Data on state politics and elections are presented, as well as codebooks associated with each dataset." econ and political data, all 50 states