Buying art: you can post bids on art for auction in threads under Artwork section of the forum, and you can post orders for art in threads under the Adoptables or Art Shop sections of the forum. Make sure you have enough mush / apples to pay the artist. To send mush, go to the player's den space by clicking on their username and click Send Mishrooms or Send Apples.
Selling art: you can make an art shop, adoptable shop, or host an art auction by creating a new forum topic. The art must be yours (although you can use free-to-use linearts) and must be properly credited. Image must be uploaded to an acceptable image hosting site, no hotlinking is allowed.See here for help:
Art Crediting: https://wolfplaygame.com/forums.php?f=4&t=1
All about Art: https://wolfplaygame.com/forums.php?f=4&t=100
Winter Month: 1 
Day 
Fog
