The Earthen Ring is a strong side faction in wow, with a nice background, also there is a realm called Earthen Ring, RP realm.
In cataclysm, they get a nice role, in Vashj’ir zone, their tabard quartermaster vendor is located in Shimmering Expanse, in Silver Tide Hollow, is an actual underwater cave, if you follow the quests there, you will get there. And if you finish all the quests in Vashj’ir you will end up with having honored reputation with the Earthen Ring, meaning you can buy the first set of items.
Also the Earthen Ring is the best faction to start leveling if you are a hunter, or rogue maybe, they got a nice epic high end dps ring.
To get reputation with them do dungeons wearing their the Earthen Ring tabard, you will need to have friendly reputation with them in order to get it, as every tabard since wrath of the lich king.