Nonprofit (or not-for-profit) organizations are not required to disclose information, such as financial and personnel documents. By law, they are not held to the same requirements as for profit entities. Therefore, there is often less documentation available to the public.
Despite the fact that these organizations do not have the same disclosure requirements, many still publish annual reports and other documentation on their organization's activities. The best resources to find such information is to go directly to the organization's website, or search for them in a database such as GuideStar (see below information on accessing GuideStar).