What is it?
The Auction House allows one to sell items for a fixed price that others can buy. It shows the main menu, from which you can browse items, and see recently sold items.
/ah- open the auction house
/ah search <term>- searches the Auction House for <term>
/ah sell <price>- lists the item in your hand for sale for <price>
/ah selling- view the items you are selling
/ah sold- view the items you have sold recently
/ah expired- view your expired items to return
/ah cancel- cancel all your auctions
/ah return- return all your cancelled/expired items