When using statistics, ensure you're using them responsibly. Rather than look for numbers to confirm what you already believe, ask yourself an open ended question, and then find the numbers to answer that question one way or another--and not necessarily the way you expected. Not sure? Ask your professor--or a librarian.
A portal to U.S. government's vast wealth of statistical data. From here find agency websites offering data on a broad range of topics, including agriculture, engineering, labor, national resources, and more. Although data.gov has become the government's primary data repository, it is undergoing transition, and this site is often easier to navigate.
Whether you're looking for data to inform your research in health, science, sociology, politics, business, or elsewhere, start with these multidisciplinary data powerhouses.
As a giant nonpartisan information gatherer, Pew Research Center offers data, analysis, and interactive tools on American society, politics, religion, race, media, internet and technology use, public libraries, and more.