In the crafting district there are three main shops:
The Smith
The Smith's Shop allows you to smelt your Iron, Gold and Silver Nuggets into Cubes of the respective materials used. This can be accomplished by using the Furnace.
You can also use the Anvil to craft new Iron Weapons and Armors using the Formulas you have in your possession.
Finally, you can also use the Customization Bench to modify the appearance of your Weapons (Including Shields) while also improving their Stats.
The Woodworker
The Woodworker's Shop lets you use the saw to cut your wood logs into wood cubes.
You can also find a workbench which allows you to craft weapons using wood as their primary material, such as Staves and Bows.
Sewing shop
At the sewing shop you can find the spinning wheel and the loom, for creating linen and silk.