The GuideStar database provides an extensive list of Non-Profit organizations that includes a summary of their organization structure and purpose as well as key financials and programs. This is a great place to get started.
Searching for information on non-profit companies is much different than finding information on a publicly traded company because non-profits are not required to file annual reports.
Nonprofit organizations with 501(c)(3) status are required to file Form 990, Return of Organizations Exempt from Income Tax, with the IRS. The form includes financial statements and background information on the nonprofit, including salaries of key employees (i.e. director, head, officers).
Although these reports are not as detailed as the annual report or 10-K reports, the following sites are a good place to start in order to obtain background information on a non-profit company:
http://foundationcenter.org/find-funding/990-finder
990 Finder gives you free access to nearly 3 million of the most recent Forms 990 and 990-PF filed by nonprofit organizations with Internal Revenue Service (IRS).
This website is managed by The Better Business Bureau (BBB). The BBB Wise Giving Alliance helps donors make informed giving decisions and promotes high standards of conduct among organizations that solicit contributions from the public. It produces reports about national charities, evaluating them against comprehensive Standards for Charity Accountability, and publishes a magazine, theWise Giving Guide, three times a year.
BBB WGA does not rank charities but rather seeks to assist donors in making informed judgments about those that solicit their support. Evaluations are done without charge to the charity and are posted for free public access on give.org.
https://www.charitynavigator.org/
Founded in 2001, Charity Navigator has become the nation's largest and most-utilized evaluator of charities. In our quest to help donors, our team of professional analysts has examined tens of thousands of non-profit financial documents. We've used this knowledge to develop an unbiased, objective, numbers-based rating system to assess over 9,000 of America's best-known and some lesser known, but worthy, charities.