With that kind of volume, I'd start with a yard sale. If you don't have enough other "stuff" to fill the sale, do it with friends or neighbors. Try to have items accessible (not in boxes under tables). Suggestions would be out on a table or hanging on hangers on a makeshift clothesline. Most yardsales here hang the nicer items (dresses, coats, etc), and you could replenish the hanging items as things sell.
With the leftovers, I would do a Children's consignment sale, which may mean you have to wait until end of Summer rolls around. Though sales are different in every area, ours take place at the end of seasons for the following season: February and March for Spring/Summer items, August/September for the Fall sales.