How do merchant accounts work?

You explained it very well. I have an online merchant acct. but I don't understand how to let the customers know I take credit cards & in what part of my website do I collect their information...

Paypal Merchant Account

Hi, I have a merchant acct. If my customers want to pay with their credit card & not paypal, which button do they click on to finish the sale? There is no button that says "pay by credit...