You receive this quest from Horde in the Forge.
Kill the warrior in the village.
They will drop the forge key.
Use the key to unlock the door to the forge and enter the forge.
Talk to Horde.
He will ask you to get him a Fireproof Chest.
You will receive the Fire up the Forges quest.
To get the Fireproof Chest, go to the different cities on the Island and visit their Inns. Remember to save before going into each Inn, so if they don't have it, you can keep reloading that save until they do.
Return to Horde in the forge in Ironworkers' Guild.
You will lose the Fireproof Chest.
The Fire up the Forges quest will be solved.
The forges to the left and right behind Horde will light up and will now be available to use.
You need 10 Iron ore or 10 ? ore to use them.
You can get iron ore from killing Warrior Maidens.
I found a lot of Warrior Maidens in the Bay of the Fisherfolk Zone and other surrounding zones.
When you have 10 iron ore or 10 ? ore, go back to the forge.
Hit the left forge with your weapon to use your iron ore to make a Iron Sword (Heavy Weapon), Iron Shield (Heavy Armor), or Iron Mail (Light Armor).
Hit the right forge with your weapon to use your ? ore to make ?