Secretary of State - contains a list of Oklahoma nonprofits & is the place where you annually register your nonprofit

Alliance for Justice – a national association of more than 100 organizations dedicated to advancing justice and democracy.

Internal Revenue Service – contains a section dedicated to information for the nonprofit sector.

National Council of Nonprofits – the nation's largest nonprofit network with more than 24,000 member organizations across the country.

Urban Institute - gathers data, conducts research, evaluates programs, offers technical assistance overseas and educates Americans on social and economic issues to foster sound public policy and effective government.