To add new terms:
Log in as user with the site admin role.
Open the admin wrench and navigate to Structure > Taxonomy.
To add a term click "Add term" in the row for the appropriate vocabulary.
Type the term name into the "Name" field and click "Save."
To create a hierarchy of terms or reorder terms:
Log in as user with the site admin role.
Open the admin wrench and navigate to Structure > Taxonomy.
Click "List terms" next to the vocabulary.
Drag and drop to up and down to re-order.
Drag left and right to create hierarchies.