Halstatt, Inc.
Offers to amend tax returns to recover unclaimed deductions.
Internal Revenue Service
Provides tax information and forms for U.S. businesses.
Nolo
http://www.nolo.com/lawcenter/index.cfm/catID/19B45DBF-E85F-4A3D-950E3E07E32851A7/subcatid/AC0056C4-
Business tax legal issues explained for LLCs, corporations, sole proprietorships.
SBA Office of Advocacy
Provides information on taxes and legal issues for small businesses.
StartupJournal - Tax and Legal Advice
Presents articles on taxation.
Tax Reduction Institute
Provides seminars and tapes on business taxation.