The Nonprofit FAQ

American Institute of Philanthropy

http://www.charitywatch.org/

BBB Wise Giving Alliance

http://www.give.org

Charity Navigator

http://www.charitynavigator.org/

Standards for Excellence Institute created by Maryland Nonprofits

http://www.standardsforexcellenceinstitute.org/

the Combined Federal Campaign (CFC)

http://www.opm.gov/cfc/

(The report explains that the CFC is included because "it identifies standards a nonprofit group must meet in order to solicit donations (via the CFC)
from federal employees.")

Extensive tables in the report present details -- so far as they could be determined -- about the standards, procedures and administration used by those organizations.

As the report explains, there are other 'watchdog' groups that cover more limited territory. The Charities Review Council in Minnesota (http://www.crcmn.org/) provides information on organizations that are active in that state. The Evangelical Council on Financial Accountability (http://www.ecfa.org) certifies the financial reporting of evangelical ministries.