Where can I get official information for federal payroll taxes?
For official information on federal payroll taxes we recommend the Internal Revenue Service Publication 15 which is known by two names: Circular E and Employer's Tax Guide. This free publication is available at the website IRS.gov.
The Employer's Tax Guide is updated each year by the IRS and contains approximately 70 pages of information on payroll. The information includes required withholdings, employer's payroll taxes, required reporting, federal income tax withholding tables, and more.