Maybe my checkout wizard is different from yours, but I can get all the way up to the step where it summarizes everything (even shipping cost) before I actually submit the order.
No major internet distributor of anything forces you to supply payment without letting you see everything else. When you enter your information, your not saying "charge my card." At the very end of the process, it'll show you what Softnerd said, a summery sheet, that shows you taxes (for us lucky states,) shipping, the item, and anything else, next to a button that says "complete my order" or "charge my card"
Yes, Amazon will take a Visa gift card.