On our server you can setup a shop in the following steps:
- Place a chest.
- Leftclick the chest with the item you want to sell. (this should give you a message with the question for how much you want to sell the item)
- Open your chat menu with "t".
- Type the price you want to sell your item for in the chat.
- Put the items in the chest.
- Punch the sign to update the amount.
To be able to create more shops you could go to the dogcraft website to the shop to extend the amount of shops you could make. Also you could hire a mall plot from the website.