Unlike other MMOs such as WoW or Final Fantasy who use a community board or centralized auction house for trading, The Elder Scrolls Online has a rich economy with individual publicly accessible Guild Traders scattered throughout the world.
In ESO, there are over 200 guild traders scattered across Nirn. Traders are secured by guilds through a weekly bidding process. Each guild can only hold one trader at a time. Guilds are never guaranteed to have a trader so there is a chance a guild could lose a trader or the location they have could differ from week to week. While any guild with 10 members can have a guild store, they are not publicly facing store fronts and can only be accessed by other guild members.
HOW TO BUY FROM A TRADER
To use a trader you will interact with them as you would with any other shop NPC. Clicking the "Guild Store" dialog will bring you into the shop. Here, it will also tell you what guild owns that particular trader. Search for the item you are looking to buy, click purchase, and the item will be immediately delivered via your in-game mail.
HOW TO SELL ON A TRADER
Are you part of a guild that has a trader? There are the two ways to access your trader and list your items for sale. Your first option is to visit the trader in person at their shop location. The second option is to go to any standing bank. Note: you cannot access your trader through your personal banking assistant.
Once you access your store, you'll have an option for "Guild Store". IMPORTANT: Make sure you select the guild you want to list the item(s) in from the drop down menu at the bottom first, otherwise your items will not be listed in the correct store. From here, you can browse from your guilds store, even if they don't have a trader. You can also list items to sell, and view your own listings.
HOT TIP: If you are on PC there are a few addons to help price your items properly to maximize your profits. Arkadius trade tools, Master Merchant and Tamriel Trade Center are a few of the one’s we use to help us.
Good luck and happy trading!