Mining

Horde

All (to 300)
Makaru (Valley of Honour, Orgrimmar)
Brom Killian (The War Quarter, Undercity)
Brek Stonehoof (Thunder Bluff, South West part)
Johan Focht (The Sepulcher, Silverpine Forest)
Krunn (Razor Hill, Durotar)

Master (to 375)
Krugosh (Thrallmar, Hellfire Peninsula)

Alliance

All (to 300)
Matt Johnson (Darkshire, Duskwood)
Geofram Bouldertoe (The Great forge, Ironforge)
Yarr Hammerstone (Kharanos, Dun Morogh)
Gelman Stonehand (Dwarven District, Stormwind City)
Brock Stoneseeker (Thelsamar, Loch Modan)
Dank Drizzlecut (Gol'Bolar Quarry, Dun Morogh)
Kurdram Stonehammer (Auberdine, Darkshore)

Master (to 375)
Hurnak Grimmord (Honor Hold, Hellfire Peninsula)



*How to Smelt Dark Iron

Where do I learn to smelt Dark Iron?

You need to speak to Gloom'rel in Blackrock Depths. After you exit the bar, head down the steps and take the first left, which is Flamelash's room. Contine on past him and into the next room until you come to a tomb with 7 ghosts. Gloom'rel is one of the ghosts. Speak to him and then use the tribute pyre next to him. He will ask you for 20 Gold Bars, 2 Star Rubies and 10 Truesilver bars.

Where do I smelt Dark Iron

Dark Iron can only be smelted at the Black Forge within Blackrock Depths. This is located near the end of the instance by the Molten Core entrance.
It takes 8 Dark Iron Ores to make 1 Dark Iron Bar.
To use the Dark Iron Bars, you need to use the Dark Anvil, which is located in the centre of BRD, where Lord Incendius spawns.


How to Smelt Elementium

Thought I'd better add this now, as some new AQ items require Elementium and not just Thunderfury.

To learn to smelt Elementium, you need to find Krixix in Blackwing Lair. He's just before Ebonroc. He has three level 63 mobs with him, so you need to sheep him and kill the mobs. Once they are down, mind control Krixix and then cast the "Smelt Elementium" buff on one of your miners in the raid (you did bring one, didn't you?). That person can now smelt Elementium.
To smelt it, your going to need the following:
1x Elementium Ore
10x Arcanite Bar
1x Fiery Core
3x Elemental Flux

The ore drops from Technicians in Blackwing Lair. You can pull loads of them from Firemaws room and wait for respawns, as these mobs do respawn.