Clothing should be clean, folded (not stuck in a plastic garbage bag), with no stains, rips, runs, pills, etc... Basically, only bring in stuff YOU would be willing to pay for.
Depending on the amout of items brought in you may be asked to leave them at the store for the staff to go through. You will recieve a call within a week informing you of the amount of Store credit that will be issued. The store credit does not have to be used right away and never expires.