You'll probably have to pay customs on the items, but only on the price that you purchased them at, and there are broad exemptions for small-ticket items being brought into the US. the US customs website will have details
as for the business, Id recommend starting simple and cheap by using etsy.com to sell your goods. they have an established base of clientele all interested in handmade goods, so you'll have a ready group of customers. Its kind of like ebay for handicrafts and vintage goods....very limited startup costs, and you'll be able to see what sells well without having to lay out a lot of dough!
let us know if you have other questions, I think this is a great idea and I'd love to help you brainstorm...