I need to know how to close out sales discounts:confused:

Because it is a contra revenue account, and therefore a debit, you will close it out with the other debits. That is, it's closed with the expense accounts.

(That isn't the only way it can be done, but that's the way I've seen it done. As long as it gets credited out of there and debited into income summary in some way, shape or form, it won't really matter.)