You can put up your items and AP for trade in the Trades center. You can have up to 5 separate trades at a time and 10 different items for trade, although there is no limit of how many of each item you can put in the trade. You can include a wishlist for your trade. There is currently no time limit for how long a trade may stay active. You are notified via the Events Manager when you have an offer, or when an offer is cancelled.