If you wish to setup Taxes, go to:
Settings -> Billing -> Taxes -> Add Tax
Add/Edit Tax Rule
Name: Insert Tax name, such as "Sales Tax".
* Country: Select which Country this tax will apply to. If every Country should receive the tax rule, select All (Make default).
** Division: Which State or area should this apply to. If the entire Division/State/Area should receive the tax rule, select All (Make default).
Tax (%): Select the percentage of the total price that is taxable.
* If a tax rule is applied to all countries, it will be the default tax unless otherwise specified.
** If a tax rule is applied to all states, it will be the countries default tax unless otherwise specified.