IRS

Forms and publications
http://www.irs.gov/formspubs/index.html

Charities and Non-profits
http://www.irs.gov/charities/index.html

Businesses
http://www.irs.gov/businesses/index.html

Individuals
http://www.irs.gov/individuals/index.html

Government Entities
http://www.irs.gov/govt/index.html

NABA
http://www.nabainc.org/pages/Home.jsp

GA Society of CPA's
http://www.gscpa.org/

GA Dept of Revenue
http://www2.state.ga.us/departments/dor/#