Catalog of Federal Domestic Assistance
Gives you access to a database of all Federal programs available to State and local governments; domestic public, quasi-public, and private profit and nonprofit organizations and institutions; specialized groups; and individuals.

GovBenefits.gov
GovBenefits.gov is the official benefits website of the U.S. government, with information on over 1,000 benefit and assistance programs.

Grants.gov
Grants.gov is your source to FIND and APPLY for federal government grants.

PowerHomeBiz.com
Disusses grants for your business and some ways to search for funding.

Small Business Administration
Includes links to a number of grants for businesses.