I'm not sure where you live, but there is a company in New England that handles clothing drives for schools. You can find them by googling "Easy Clothing Drive" and they pay by the pound for clothes collected too.
Our H.S.A. will be holding a Clothing Drive in November during a family fun night dance. We are going to have the families in our school drop off unwanted clothing and shoes the week before the drive. We plan to sell the clothing for $1 each and whatever is left over we where going to contact a company to pick up. I've seen companies that will pay .15 per lb. does anyone know of other companies?