GuideStar
Free service with information on the programs and finances of more than 650,000 American charities and nonprofit organizations.
The Jewish Communal Fund
Provides donors the opportunity to simplify their charitable giving and maximize tax savings through the use of donor-advised funds.
National Center for Charitable Statistics (NCCS)
National repository of data on the nonprofit sector in the United States. Its mission is to develop and disseminate high quality data on nonprofit organizations and their activities.