An option is the U.S. Government website www.grants.gov, which provides links to federal grants. These can be browsed by category, funding agency, or eligibility.
Finally, Howard-Tilton has a collection of print resources on our "ready reference" shelves in the first-floor Learning Commons. The series Money for Graduate Students in... focuses primarily on financial aid opportunities, but each volume also includes a listing of research grant sources for graduate student projects.
This library guide is intended to be an introduction to finding and applying for grants, funding, and scholarships opportunities from Federal agencies, private funders, and here at Tulane University.