So you're familiar with eBay...you're there everyday. An eBayer you are; a web designer you are not. I've seen way too many people get pulled into the lie that if you can sell on eBay, you can design, update, maintain (do anything to, really) a website. eBay has made millions by making selling easy. Follow a few steps, and la-di-da, you're done. But you've only created a paragraph of code in an encyclopedia of HTML.
If you don't know what HTML is, you've just had your first clue that you need serious training before attempting anything with a website. Check out "Words to Live By" at Newbie.org. Unless you know all of the terms listed there, Please do not try this at home!