Depending on the hospital, they might actually give you some stuff... But to be on the safe side you'll want to bring a couple diapers (newborn or even premie size), a hat, mittens, a little outfit (I did footie pajamas) and a blanket for baby to come home in.
For you, you'll want something comfortable, a robe or pajamas, clean panties, something to wear home, travel sized shampoo and soap... And I don't remember what else I took with my first.