BBB Wise Giving Alliance
BoardSource
Center for Excellence in Nonprofits
CharityChannel
Charity Navigator
Craigslist Foundation
The Chronicle of Philanthropy
CompassPoint BoardCafe
The Foundation Center
Global Giving
GuideStar.org
Idealist.org
Independent Sector
Nonprofit Genie
NonProfit Times
PNN Online
Salesforce.com Foundation
Universal Giving