Give me the Quick an Dirty on E-Commerce

I am ready to start doing an E-commerce Web Site,
I checked around the web I found Services like Pay-pal, and some other services which will “Hook me up” but what I really want to know is HOW do I get a Shopping Cart Linked into My Pages that I create. Do I create the Pages within some Shopping Cart Program that works kinda like Front page? Or do I Link what I create with a Server Based Shopping Cart someplace, and which way is the best way to do it?
I’m looking for the Cheapest way to do it,this is My first E-commerce site, and I want it to work well, but I don’t want to pay a fortune for any Services to make it happen. Fill me in ok?