WoW Blacksmithing Profession Guide
Blacksmithing allows the player to craft armor and weapons for himself and other players. When you raise your Blacksmithing skill you will eventually be able to choose a specific craft as to which you would like to specialize. For example, if you want to be able to make better weapons, choose weapon smithing. If you want to make better armor, choose Armor Smithing. Blacksmithing best supports plate wearers and anyone who's main form of damage comes from a weapon.
Added in WoW's second expansion, Blacksmiths are able to create a 
Eternal Belt Buckle. Any character can use this and it adds a socket to any belt item. If you choose Weaponsmithing as a Blacksmith you will be able to further specialize your skill into Sword Smithing, Mace Smithing or Axe Smithing. Below I've compiled information on quests to advance your skill.
Blacksmithing Paths
Weaponsmith - Allows a blacksmith to make special weapons that are unavailable to the typical blacksmith.
In order to become a Weaponsmith you must Complete the quest "The Way of the Weaponsmith". To complete this quest you need the following;
Moonsteel Broadswords x 4
Massive Iron Axes x 4
Heavy Mithril Axe x 2
Big Black Mace x 2
For Alliance you can get this quest from Ironus Coldsteel in Ironforge. For Horde you can get this quest from Borgosh Corebender in Orgrimmar.
Master Axesmith - Allows a blacksmith to make special axes that are unavailable to the typical artisan weaponsmith.
To train in Master Axesmithing talk to Kilram in Everlook in Winterspring.
Master Hammersmith - Allows a blacksmith to make special maces and hammers that are unavailable to the typical artisan weaponsmith.
To train in Master Hammersmithing talk to Lilith in Everlook in Winterspring.
Master Swordsmith - Allows a blacksmith to make special swords that are unavailable to the typical artisan weaponsmith.
To Train in Master Swordsmithing talk to Seril Scourgebane in Everlook in Winterspring.
Armorsmithing - Allows a blacksmith to make special armors that are unavailable to the typical blacksmith.
In order to become a Armorsmith you must complete the quest "The Art of the Armorsmith". To complete this quest you need the following;
Ornate Mithril Helm x 4
Ornate Mithril Boots x 2
Ornate Mithril Breastplate x 1
For Alliance you can get this quest from Grumnus Steelshaper in Ironforge. For Horde you can get this quest from Okothos Ironrager in Orgrimmar.
Leveling Blacksmithing 1 - 450
To train the Blacksmithing skill ask a guard in any of your factions main cities, to be redirected to a trainer.
Blacksmithing 1 - 30
Craft - 
[Rough Sharpening Stones] x 30
Materials Required:
33 Rough Stones
Blacksmithing 30 - 65
(Save 10 of these for later)
Craft - 
[Rough Grinding Stones] x 50
Materials Required:
100 Rough Stones
Blacksmithing 65 - 75
Craft - 
[Copper Chain Belt] x 10
Materials Required:
60 Copper Bars
Blacksmithing 75 - 200
Blacksmithing 75 - 87
(Saves these)
Craft - 
[Coarse Grinding Stones] x 12
Materials Required:
24 Coarse Stones
Blacksmithing 87 - 100
Craft - 
[Runed Copper Belt] x 13
Materials Required:
130 Copper Bars
Blacksmithing 100 - 105
Sell these on the Auction House.
Craft - 
[Silver Rod] x 5
Materials Required:
5 Silver Bars
10 Rough Grinding Stones
Blacksmithing 105 - 125
Craft - 
[Rough Bronze Leggings] x 20
Materials Required:
120 Bronze Bars
Blacksmithing 125 - 150
Craft - 
[Heavy Grinding Stones] x 50
Materials Required:
150 Heavy Stone
Blacksmithing 150 - 155
Sell these on the Auction House.
Craft - 
[Golden Rod] - x5
Materials Required:
5 Gold Bars
10 Coarse Grinding Stones
Blacksmithing 155 - 165
Craft - 
[Green Iron Leggings] x 10
Materials Required:
80 Iron Bars
10 Heavy Grinding Stones
10 Green Dye
Blacksmithing 165 - 190
Craft - 
[Green Iron Bracers] x 25
Materials Required:
150 Iron Bars
25 Green Dye
Blacksmithing 190 - 200
Craft - 
[Golden Scale Bracers] x 10
Materials Required:
50 Steel Bars
20 Heavy Grinding Stone
Blacksmithing 200 - 275
Blacksmithing 200 - 205
Craft - 
[Truesilver Rod] x 5
Materials Required:
5 Truesilver Bars
5 Heavy Grinding Stones
Blacksmithing 205 - 210
Craft - 
[Solid Grinding Stone] x 15
Materials Required:
60 Solid Stones
Blacksmithing 210 - 225
Craft - 
[Heavy Mithril Gauntlets] x 15
Materials Required:
90 Mithril Bars
60 Mageweave Cloth
Blacksmithing 225 - 235
Click here to see the vendors that sell this recipe.
Craft - 
[Mithril Scale Bracers] x 10
Materials Required:
80 Mithril Bars
Blacksmithing 235 - 250
Craft - 
[Mithril Coif] x 15
Materials Required:
150 Mithril Bars
90 Mageweave Cloth
Blacksmithing 250 - 260
Craft - 
[Dense Sharpening Stones] x 20
Materials Required:
20 Dense Stone
Blacksmithing 260 - 275
Craft - 
[Thorium Bracers] x 15
Materials Required:
120 Throium Bars
Blacksmithing 275 - 350
Blacksmithing 275 - 290
This pattern is a reward from the this quest.
[Imperial Plate Bracers] x 20
Materials Required:
240 Thorium Bars
Blacksmithing 290 - 300
Etheir of these recipes will work
Craft - 
[Thorium Boots] x 10
Materials Required:
120 Thorium Bars
80 Rugged Leather
Craft - 
[Thorium Helm] x 10
Materials Required:
120 Thorium Bar
10 Star Ruby
Blacksmithing 300 - 305
Craft - 
[Fel Weightstone] x10
Materials Required:
10 Fel Iron Bar
10 Netherweave Cloth
Blacksmithing 305 - 315
Craft - 
[Fel Iron Plate Belt] x 10
Materials Required:
40 Fel Iron Bars
Blacksmithing 315 - 320
Craft - 
[Fel Iron Chain Gloves] x 5
Materials Required:
25 Fel Iron Bars
Blacksmithing 320 - 325
Craft - 
[Fel Iron Plate Boots] x 5
Materials Required:
30 Fel Iron Bars
Blacksmithing 325 - 330
Craft - 
[Lesser Rune of Warding] x 7
Materials Required:
7 Adamantite Bars
Blacksmithing 330 - 335
Craft - 
[Fel Iron Breastplate] x 5
Materials Required:
50 Fel Iron Bars
Blacksmithing 335 - 340
To see the list of vendors that sell these plans, click here.
Craft - 
[Adamantite Cleaver] x 5
Materials Required:
40 Adamantite Bars
Blacksmithing 340 - 350
Click here to see a list of vendors that sell these plans.
Craft - 
[Lesser Ward of Shielding] x 10
Materials Required:
20 Adamantite Bars
Blacksmithing 350 - 400
Blacksmithing 350 - 360
Craft - 
[Cobalt Belt] x 10
Materials Required:
40 Cobalt Bars
Blacksmithing 360 - 370
Craft - 
[Cobalt Bracer] x 10
Materials Required:
40 Cobalt Bars
Blacksmithing 370 - 375
Craft - 
[Cobalt Helm] x 5
Materials Required:
25 Cobalt Bars
Blacksmithing 375 - 380
Craft - 
[Cobalt Gauntlets] x 5
Materials Required:
25 Cobalt Bars
Blacksmithing 380 - 385
Craft - 
[Spiked Cobalt Boots] x 5
Materials Required:
35 Cobalt Bars
Blacksmithing 385 - 390
Craft - 
[Sure-fire Shuriken] x 5
Materials Required:
35 Cobalt Bars
Blacksmithing 390 - 395
Craft - 
[Notched Cobalt War Axe] x 5
Materials Required:
50 Cobalt Bars
Blacksmithing 395 - 400
Craft - 
[Brilliant Saronite Belt] x 5
Materials Required:
30 Cobalt Bars
25 Saronite Bars
Blacksmithing 400 - 450
Blacksmithing 400 - 405
Craft - 
[Horned Cobalt Helm] x 5
Materials Required:
40 Cobalt Bars
Blacksmithing 405 - 410
Craft - 
[Brilliant Saronite Boots] x 5
Materials Required:
60 Saronite Bars
Blacksmithing 410 - 415
Craft - 
[Tempered Saronite Bracers] x 5
Materials Required:
70 Saronite Bars
Blacksmithing 415 - 525
These will easily sell at the auction house, allowing you to get most of the gold you spent back. If you'd like to make some gold off this click here to see the best places to farm the Eternal Essences.
Craft - [Eternal Belt Buckle] x 13
Materials Required:
52 Saronite Bars
13 Eternal Earth
13 Eternal Shadow
13 Eternal Water
Blacksmithing 425 - 455
Craft - 
[Folded Obsidium] x 80
Materials Required:
160 Obsidium Bars
Blacksmithing 455 - 458
Craft - 
[Stormforged Gauntlets] x 1
Materials Required:
6 Folded Obsidium
8 Volatile Earth
Blacksmithing 458 - 459
Any recipe that requires 3 Folded Obsidium.
Blacksmithing 459 - 462
Craft - [Stormforged Gauntlets] x 1
Materials Required:
6 Folded Obsidium
8 Volatile Earth
Blacksmithing 462 - 470
Craft - 
[Stormforged Belt] x 8
Materials Required:
32 Folded Obsidium
8 Volatile Earth
Blacksmithing 470 - 475
Craft - 
[Obsidium Bladespear] x 1
Materials Required:
12 Folded Obsidium
10 Volatile Earth
4 Volatile Fire
Blacksmithing 475 - 480
Craft - 
[Elementium Rod]
Materials Required:
45 Elementium Bars
Blacksmithing 480 - 489
Craft - 
[Stormforged Legguards] x 3
Materials Required:
6 Folded Obsidium
24 Elementium Bars
Blacksmithing 489 - 494
Craft - 
[Fire Etched Dagger] x 1
Materials Required:
20 Elementium Bar
12 Volatile Earth
4 Volatile Fire
Blacksmithing 494 - 500
Craft - 
[Stormforged Helm] x 2
Materials Required:
40 Elementium Bars
16 Volatile Earth
Blacksmithing 500 - 511
Craft - 
[Redsteel Breastplate] x 4
Materials Required:
80 Elementium Bars
80 Volatile Earth
Horde players will need to buy recipes from Kuldar Steeltooth at Dragonmaw Port in Twilight Highlands.
Alliance players will need to buy recipes from Brundall Chiselgut at Highbank in Twilight Highlands.
Blacksmithing 511 - 515
Craft - 
[Ornate Pyrium Gauntlets] x 4
Materials Required:
40 Elementium Bars
40 Volatile Water
Blacksmithing 515 - 520
Craft - 
[Ornate Pyrium Belt] x 5
Materials Required:
50 Elementium Bar
50 Volatile Water
Blacksmithing 520 - 525
Craft - 
[Ornate Pyrium Shoulders] x 5
Materials Required:
Elementium Bar
50 Volatile Water
Choosing a Second Profession
With Blacksmithing there really is no proper choice for a second crafting profession. However I will say leveling Blacksmithing without Mining is hell since you won't be able to smelt your own ore, or mine it. I'd highly recommend going Mining along with Blacksmithing, if not, pick Enchanting.
The only reason I don't say grab Jewelcrafting is, Enchanting will benefit you better. Blacksmithing allows you to add two extra sockets to your gear, but Jewelcrafting only allows 3 extra potent gems. Which you will use these extra potent gems up, even before you get to the extra sockets.
Extra Benefits to Blacksmithing
Aside from the Belt socket, which everyone can use. Blacksmiths are also able to socket their belts and bracers. To see the sockets, click on their respective link below.
Profiting Off Blacksmithing
Blacksmithing is one of the most difficult professions to profit off of. The only thing viable for you to make money off of 425+ is Belt Buckles. You may also be able to sell the blue tanking gear that you make, but this won't sell nearly as well as the Belt Buckles. Again, if you'd like to see the best spots to farm Eternal Essences, to help you profit off the Belt Buckles, click here.