Go to Vital Law database by CCH. 

• Expand the 'State Tax' section.
• Then expand the 'State Tax Guide' section.
• Expand the 'Sales and Use -- State Summaries' section.
• Choose which state interests you and select 'Rates.'

See also the Federation of Tax Administrators website for state comparisons of income, sales, and excise tax rates.

Downloadable tax forms are also available on the State of Illinois site.