The Taxes button is where you can view and manage what your current tax rate is.
When you are in the Tax management screen double-click or single-click and hit manage.
The Manage Tax window will appear allowing you to view or manage your Tax.
The Example above is showing the tax rate is currently 3.7.
Double-click or single-click and hit Manage or hit Add to set up a new Tax rate.
You can Limit by date range to set up events like Tax free weekend
Limit by value range is if you had a tax rate, that was 1ยข - $100 is one tax rate, $100.01 - $500 is a different tax rate, this could be set here.