Deadmines
First off why goto an instance at all? They are much more difficult than other areas of the game, usually give lower xp than soloing as well. Pretty much they are just for loot and quests that give you loot.
Here are a list of all deadmines related quests.
These are the quests that are not in the instance, but are in the mine area outside. You have to fight through some elite defias around level 17-19 and then fight some skeletons to a boss zombie for Oh Brother, the memories can be collected off any of the undead at random. You get both of these quests from the same NPC in the Dwarf District of SW. You can pull up a map on thott. Collecting Memories - Reward is Mail boots or Leather Gloves. Oh Brother. . . The reward is a 2h Axe
There are 2 quests inside the instance. One is to kill a goblin shredder (A required boss to advance). The other is to kill VanCleef the last boss of the dungeon. Underground Assault gives mail gloves or a wand. The Defias Brotherhood This gives very good rewards. Mail pants, Leather Tunic or a Staff. This starts as a quest line from Stoutmantle in Westfall at level 14 and has the same name at the beginning of the quest line.
So what other items can you get from this instance? Well here is a list I made. This does not include world drops, that you will likely see a few of, since they are so random you cannot rely on ever seeing one. Nor are the unique to Deadmines.
[b]Rhak'Zor[/b] This is the first boss you fight. He is immune to cold and is a pretty easy fight. Just don't rely on frost nova to get aggro off you as a mage. Rhak'Zor's Hammer
[b]Sneed's Shredder[/b] Sneed's Shredder is not immune to cold or snares. This leaves a lot of options open for kiting. Back when talents first went in I could solo him pretty easily as a mage at level 18. Buzzer Blade Common Drop Buzz Saw Rare Drop
[b]Sneed[/b] After killing the Shredder you have to fight the pilot. The only difficult part about fighting him is not expecting another fight immediatly after the last. Gold-flecked Gloves Common Drop Taskmaster's Axe Rare Drop
[b]Gilnid[/b] This boss always comes with an add or two. You should focus on the adds first, since they are pretty easy to take down. Also just try to keep good aggro on all adds so your healer doesn't get hit when they start healing. Smelting Pants Common Drop Lavishly Jeweled Ring Rare Drop
[b]Mr. Smite[/b] Smite is a Tauren Warrior with warstomp. He usually has 2 adds from the stealthed defias near him. Kill the adds first, because Smite's DPS just goes up through the fight. At the beginning he isn't much of a problem, and the adds are a lot quicker to kill than him. Smite's Reaver Common Drop Thief's Blade Common Drop Smite's Mighty Hammer Rare Drop
[b]Cookie[/b] He is a murloc and the ship's cook. Most groups skip him but you can find him around the backside of the ship. Cookie's Tenderizer Common Drop Cookie's Stirring Rod Rare Drop
[b]Captain Greenskin[/b] This is the last boss before VanCleef and he patrols the top decks of the ship. Impaling Harpoon Common Drop Emberstone Staff Rare Drop
[b]Edwin VanCleef[/b] This is what you have been waiting for. He spawns 2 bodyguards, and 2 more later in the fight. Best to take out the bodyguards fast so you do not get overwhelmed. Corsair's Overshirt Common Drop Cruel Barb Common Drop Cape of the Brotherhood Rare Drop Blackened Defias Armor Rare Drop