Innkeeper
From WoWWiki
An innkeeper is an NPC, typically inside an inn, that offers characters the opportunity to bind their souls at the npc's location, so that the character's [Hearthstone] will returned them to that spot later when used. Most innkeepers are also either general goods vendors or food and drink vendors, though some innkeepers do not sell anything at all.
To set or change the bind point for your hearthstone, talk to an innkeeper and click make this inn your home.
As of Patch 2.3, your pointer changes when you move it over an innkeeper NPC who you can bind to:
interact with innkeeper 
innkeeper out of range
