U.S. Government Tax Webpages

• Internal Revenue Code of 1986 - Title 26 of the U.S.C., from Cornell (searchable)
• The Code On-Line - searchable; check "weasel words" for coverage dates
• US Tax Court
• Internal Revenue Service
• Multistate Tax Commission - 44 states and D.C. - "to preserve federalism and tax fairness".

Massachusetts State Tax Information

• Massachusetts Department of Revenue Home Page - with links to rulings and regulations
• Massachusetts Tax Forms and Publications - Mass. Department of Revenue