Below are resources for starting and maintaining your nonprofit organization (a.k.a. NPO, not-for-profit organization, public service organization or 501(c)3 corporation) in compliance with IRS and other laws.
Internet Nonprofit Center (INC) Fabulous set of links to a huge number of nonprofit issues, including organization, management, regulation, development (fundraising and such), and general resources. THIS IS PROBABLY THE ONLY LINK YOU NEED.
National Council of Nonprofit Associations (NCNA) NCNA is a network of 39 state and regional associations with a collective membership of more than 20,000 community nonprofits.
Nonprofit Services Consortium addresses the needs of regional nonprofit organizations by providing access to a continuum of education, training, and technical assistance.
Guidestar Searchable database of U.S. nonprofit organizations.
Benton Foundation Mobilizes networks of researchers, practitioners, and trainers to build the communications capacity of nonprofit organizations.