How do you get in on the Auction action?
Quick Note - If you'd prefer to see this format in-game or you don't need full explanations, just type /ah help instead to bring up a menu in chat.
The Basics - Using the /ah command will open up the Auction House GUI, which is a server-wide market to allow people to sell and buy items anywhere from 1 at a time to a full stack at a time. You can either sell things for an outright price or put them up for bidding.
Learning How to Buy and Sell - To sell an item on the auction house for a flat price/buyout price, type /ah sell [price] [amount of items] while holding the item. To put an item up for bidding, type /ah bid [price] [amount of items] while holding the item. As expected, selling it for a flat price will allow people to buy it instantly, whereas putting it up for bid will allow people to bid on it and the winner gets it when the time runs out. To swap between the sell and bid screens, click the Slime Ball on the bottom row to go to the Bid option and click it again when it becomes Magma Cream to go back to the Sell option.
You Can Always Relist... (How to Collect Expired Items) - If an item doesn't sell in the allotted time or gets no bids on it, it will be taken off the sale pages. To get your item back, you type /ah expired or /ah collect to open the collection menu. Simply click on your items to get them back after that. (NOTE: Items are not saved forever in collections! Please get them ASAP!)