If you own a business, chances are, you have to pay sales or use tax. There are two components of this tax: state and local. Because local taxes vary a lot within the state and also change from time to time, it's a good idea to check the tax rates frequently.
For a quick list of state sales tax rates, consult the State Comparisons page on the Federation of Tax Administrators website.
For detailed information about state and local tax rates, use the FTA's Links to State Tax/Revenue Agency Websites Map to find your state agency.
At the tax agency website for your state, look for a link dedicated to local sales/use tax rates. Read any instructions and check the frequently asked questions section for any specific rules for your state.