IRS :http://www.irs.gov/
Comptroller ofMaryland :http://www.marylandtaxes.com/taxes.asp
District of Columbia Tax and Revenue office: http://otr.cfo.dc.gov/otr/site/default.asp
Virginia Office of Tax and Revenue :http://www.tax.virginia.gov/
Tax Advices: http://taxtopics.net/
Accounting Info: http://www.aicpa.org/Pages/Default.aspx