EBay selling one thing I don't get? Help thanks?

[Jessica]

I know you have to pay fees but how much When and on what, is it a part of the final cost when someone buys it or what? Do you not pay anything if no one buys what you list to sell, I've never sold on eBay before just bought. But I want to start selling I read the info about selling on their site and I think, think, I get the gist of how it goes but the fees they never were too clear about it just says you have to pay something sometime ? Can anyone help me here? Is it possible that if you don't get any money like no one buys what your selling that you could actually lose money on eBay from fees someone please help!!!!!