Payroll tax tables can be very confusing and change every year.  If you work with an online payroll company they will mantain these tables for you.  If you do your payroll manually or use payroll software here is some information to help you keep up:

Federal Tax:

• Department of the Treasury, Internal Revenue Service, Publication 15, Cat. No. 10000W, (Circular E), Employer's Tax Guide For use in 2011

 

State Tax:

• Each state has their own rates and rules.  For example see: Illinois Department of Revenue, Booklet IL-700-T, Illinois Withholding Tax Tables

 

Local Tax

• Many local cities and counties also have income tax.  For example check the Ohio rates at:  Ohio Department of Taxation - Municipal Income Taxes