The Academy Bonuses DLC contain :

• The Academy Bonus Bag in-game item that give the player : 3 x Card Pack, 3 x Bread, 3 x Mint Leaves, 1 x Escape Idol, Copper Talisman, Quick Shoes, Silent Horn, Elterio's Bell and Monster Repeller...
  
• The original trailer featured on Steam...
  
• 6 Pieces of artwork in both PNG & PDF format that include :
  
• The OST Cover, a Wallpaper, The Game Cover, The World Map, The Hero Card Artwork and The Book Artwork...
  
• The 28 in-game collectible cards designs in PNG including the card back artwork and the card pack artwork...

This DLC is included in the Deluxe Edition Bundle too...

To find the bonus content, locate the Steam Apps folder, open it and locate the Common folder, open it. Locate the game folder and all this content will be within the Bonus Content folder...

*If you have any problem installing this DLC uninstall the game and reinstall it at the same time as the DLC, it should fix it.*