The General Social Survey has been collected by the National Opinion Research Center (NORC) at the University of Chicago for the U.S. Government since 1972. Because of a core of repeated questions, it is possible to track shifts in public attitudes over time. There are a number of ways to access these data.
The SDA Archive hosted at Berkeley offers three ways to access GSS data: the 1972-2002 Cumulative Datafile and the 1972-2004 Cumulative Datafile via the Online Analysis System as well as Quick Tables on popular variables based on the 1972-2004 cumulative datafile. The Online Analysis System allows online cross-tabulations, calculations of means, calculations of bivariate correlations, subsetting and downloading of the data. Be sure to use the codebook (preferably, keep it open in a separate tab or window) along with the SDA Archive.
The GSSDIRS site (DIRS = Data and Information Retrieval System) offers a 1972-2000 Cumulative Codebook that is searchable and browsable in more ways than the SDA Codebook. It also offers a bibliography of published research that used the GSS.