Internal Revenue Service
- http://www.irs.gov/
- U.S. government agency responsible for tax collection and tax law enforcement. Provides downloadable income tax forms, instructions, agency publications, and "The Digital Daily," an almost-humorous online newspaper.
TaxWorld
- http://www.taxworld.org
- Includes a history of taxation, statistics, terms in different languages and a directory.
Timber Taxes
- http://www.timbertax.org/
- Comprehensive explanation of the tax treatment of timber. Including qualifying for capital gains, casualty losses, income, expenses, and reforestation.