Night Elf workers, known as Wisps, need to Entangle a Gold Mine to gather from it, which requires 60 seconds. Once assembled, Wisps could be'loaded' into wow classic gold the mine, gathering gold without having to move. Being the environmental sort, they also don't ruin trees while collecting lumber, like the other factions. Pop a wisp onto a tree, and it is going to float around collecting lumber for the remainder of the game.
The Undead also have a special gold structure -- a Haunted Gold Mine. Much like Night Elf Wisps, Undead Acolytes stay on the mine and gather mechanically. At 100 seconds, building one is slower than the Entangled Gold Mine, but Undead Acolytes don't have to stick around in one place to build, rather summoning a portal site that brings their structures into existence. When the portal is summoned, they're free to start other jobs.
Undead also differ from the other factions in that they need to use their simplest combat unit -- Ghouls -- to gather lumber. They are also much more defensible, should your opponent target your workers.
Night Elf or Undead players will find their starting mine ready to use, will not have to worry about Haunting or even Entangling immediately, until,the very first Gold Mine collapses. That's right, Gold Mines don't last forever, so you'll be looking to expand rapidly into the ancient mid-game. Find another gold mine and start planning to clean the area and enlarge to buy wow gold classic a second foundation. You also want to keep an eye for your opponent's expansions. If you have got two gold mines, and they've only got you, you're going to be in a serious advantage.