Minecraft wiki entry for Surviving_in_a_single_area_indefinitely, associated text: Do this again to another villager because at least two villagers are required for gossiping, then craft and place a grindstone, smithing table, or blast furnace to let the villagers adopt the professions of weaponsmith, toolsmith, or armorer. Trade with them till they reach apprentice or journeyman level, after which you can buy a bell. You need to trade several times and allow villagers to resupply at their job site block when their trades get locked. They can unlock their trades twice per day. If you don't have emeralds, you can trade coal. Once you buy a bell, place it near beds so villagers will recognize it as gathering site. Now you have all the supplies needed for an iron golem farm.