The Deadmines are in Westfall, in Moonbrook. The Defias Traitor will have lead you to the entrance already, but it is south (to the left) of the fountain on the road in the middle of Moonbrook.
Shoni the Shilent, Stormwind – Underground Assault
Wilder Thistlenettle – Collecting Memories
Wilder Thistlenettle – Oh Brother…
Gryan Stoutmantle, Westfall – The Defias Brotherhood
Scout Reill – Red Silk Bandanas
Jordan Stillwell, Ironforge – The Test of Righteousness (paladin only)
Shoni is close to the tram entrance in Stormwind; Wilder is also in the Dwarven District, in a building south of the tram exit. Scout Reill is at the top of the Sentinel Hill tower.
To get the Defias Brotherhood quest to kill Van Cleef, you need first to have completed the entire series of Westfall quests, including the visit to Redridge Mountains and the Defias Messenger and Traitor sequences. The continuation, with the Undelivered Letter dropped by Van Cleef, will lead you into the Stockades.
Wilder’s quests involve the 17-20 elite undead outside of the instance, in the far south of the Deadmines. The entrance to the instance is to the west, close to the undead.
Inside the instance is divided into sections, each progressively a little higher in level and harder, with a boss. The entrance to the next section only opens when the boss is killed. Killing some bosses triggers a patrol from behind – opening the door with the cannon and gunpowder is a good example of this; I think you get two mobs from ahead, and two (possibly three) in a patrol from behind. It would be a good idea to clear from the gunpower (on the left, to the north, in a side passage) all the way to the door before triggering the canon.
When you kill the shredder, Sneed will appear (apparently from inside the shredder) and attack – I have read that he can appear 20 seconds after killing, but for me it was instantly, as I looted the shredder.
On the ship at the end, there are two cases where stealth rogues are linked to a boss – entering the ship, and then Van Cleef. As well as having two stealth guards, Mr Smite also stuns you three times during the fight and swaps to higher damage weapons each time. Van Cleef will have a total of four guards, two visible, two stealthed; he may summon two of them half way through the fight.
Smite guards the gangway to the ship. The Captain takes circuits of the main deck; Van Cleef is in the shack on the top deck, and Cookie is on the far side of the main deck. The exit is directly ahead from Cookie; there are a few more mobs on the way.
Bosses
Brainwashed Noble – Girdle of Nobility (cloth waist), Staff of Nobles (staff). Both green BoE. Outside the instance.
Captain Greenskin – Emberstone Staff (blue BoP staff), Blackened Defias Belt, Impaling Harpoon (BoP polearm).
Cookie – Cookie’s Stirring Rod (blue BoP wand), Cookie’s Tenderizer (mace, BoP), Cat Carrier (Siamese).
Edwin VanCleef – Blackened Defias Armor (blue BoP leather chest), Cape of the Brotherhood (blue), Corsair’s Overshirt (blue cloth chest), Cruel Barb (blue one hand sword). All BoP.
Gilnid – Lavishly Jewelled Ring (blue BoP), Smelting Pants (green BoP leather).
Marisa du’Paige – Noble’s Robe (green cloth), Walking Boots (cloth). Outside instance.
Miner Johnson – Gold Plated Buckler (blue BoP shield), Miner’s Cape (green BoP).
Mr Smite – Smite’s Mighty Hammer (blue BoP, two handed mace), Smite’s Reaver (one handed axe), Thief’s Blade (one handed sword). All BoP.
Rhahk’Zor – Rockslicer (rare, green BoP two handed axe), Rhahk’Zor’s Hammer (white two handed mace).
Sneed – Taskmaster Axe (blue BoP two handed axe), Gold-flecked Gloves (green BoP cloth)
The item set for here is Defias Leather; basically a rogue set, but ok for hunters. The chest is BoP from Van Cleef; the rest are all BoE, but relatively rare. The belt comes from Captain Greenskin, boots from strip miners, gloves and leggings from overseers and taskmasters.