The gold ring is an important item that is required to create the ring portal and enter Middle-earth the first time. To create the ring portal, the ring item must be burned, either in lava or in fire.
The gold ring currently has no other uses and as the ring portal can only be created once, you will only need one gold ring in a game. For the future, the gold ring (along with the silver and mithril rings) will probably be used in the ring forging system.
Note: The gold ring is not intended to be the One Ring, as that and the other Rings of Power will be added at a later date.
The gold ring may also be found in chests that are in the ruins of old dwellings.
The gold ring is crafted with 8 gold nuggets in a ring shape. However, gold rings have no real purpose besides giving one passage to Middle-earth, so it is advised to spend your eight gold nuggets on something else once you are in Middle-earth (with the exception of decoration.)