You can review your order and checkout at anytime during the ordering process. It shows the order summary by tag shape and plant type by tag shape.
If you have been approved to purchase on account, you can checkout by entering a Purchase Order number or paying with a credit card.
You will need to pay with a credit card unless you have:
You can click on any of the Description links such as Gardener's XL Perennial to see the line items for that particular tag shape/plant type combination.