In addition to using information from library books and databases, you can use credible information which you find on the free internet. Make sure you evaluate information to determine if it is credible and appropriate for college-level research. If you can't decide if information is credible or not, ask your instructor or consult a librarian.
Most search engines will let you conduct an Advanced Search which allows you to you narrow your search to a restrict domain sites like .gov or .edu sites.
.gov indicates a site from a U.S. government source (local, state, or federal government)
.edu indicates a site from a college or university
The IRIS tutorial, Types of Web Resources, explains domains and how to search smarter on the web.
SCC Library research guides on particular topics have recommended websites in addition to information on finding book and database information.