Research charitable organizations
IRS.gov exempt organizations select check: Information about tax-exempt organizations, including those eligible to receive tax-deductible charitable organizations.
Guidestar.org: Information on 1.8 million charitable organizations, including access to Form 990 (requires free registration). "Form 990 is an annual reporting return that certain federally tax-exempt organizations must file with the IRS. It provides information on the filing organization's mission, programs, and finances."
BBB Wise Giving Alliance: "The Alliance does not rank charities but rather seeks to assist donors in making informed judgments about charities soliciting their support."
Charity Navigator: "By guiding intelligent giving, we aim to advance a more efficient and responsive philanthropic marketplace, in which givers and the charities they support work in tandem to overcome our nation’s and the world’s most persistent challenges."
CharityWatch.org: "A nationally prominent charity rating and evaluation service dedicated to helping donors make informed giving decisions."
GiveWell.org: Focused on finding a small number of outstanding giving opportunities, not on reviewing as many charities as possible.