Blacksmithing skill 300-305
Make Fel Weightstone (1 x Fel Iron Bar, 1 x Netherweave Cloth) x 5

Fel Iron items that you actually need to make on this speed trip to 375.

Blacksmithing skill 305-320
Make Fel Iron Plate Belt (4 x Fel Iron Bar) x 15

Blacksmithing skill 320-325

Make Fel Iron Plate Boots
(6 x Fel Iron Bar) x 5

Blacksmithing skill 325-330
Make Lesser Rune of Warding (1 x Adamantite Bar) x 10

A cheap item at this level to make, however plan to make more than 5 to get your skill points.

Blacksmithing skill 330-335
Make Fel Iron Breastplate (10 x Fel Iron Bar) x 5

Blacksmithing skill 335-340
Make Adamantite Cleaver (8 x Adamantite Bar) x 5

This recipe is a limited supply one, sold by Aaron Hollman in Shattrath City, Arras in the Exodar, or Eriden in

Silvermoon City.

Blacksmithing skill 340-345
Make Lesser Ward of Shielding (1 x Adamantite Bar) x 10

This is another cheap item to make, however it will not always give a skill point. It is however far cheaper than

any other option. This recipe is sold by Mari Stonehand in Wildhammer Stronghold for Alliance and by Rohok in

Thrallmar for Horde.

Blacksmithing skill 345-350
Make Adamantite Rapier (12 x Adamantite Bars) x 5

Blacksmithing skill 350-360
Make Adamantite Weightstone (1 x Adamantite Bar, 2 x Netherweave Cloth) x 20

While still a cheap stone skill point, this is way more expensive than the stone items your used to making. Also to

get the recipe you need honored reputation with the Cenarion Expedition, and it is fairly easy to get.

Blacksmithing skill 360-370
Make Cobalt Bracers (4 x Cobolt Bar) 10

When the launch of Wrath of the Lich King, regular players would kill to have these because they are insanely

expensive in the auction house. However, it is the easiest to level your blacksmithing right now.

Blacksmithing skill 370-375
Make Cobalt Helm (5 x Cobolt Bar) 5

World of Warcraft: Wrath of the Lich King Expansion:
For Blacksmithing 375-450, these trainers are located in Northrend.

Alliance: Valgarde, Howling Fjord Valiance Keep, Borean Tundra Frosthold, The Storm Peaks

Horde: Vengence Landing, Howling Fjord Venomspite, Dragonblight Agmar's Hammer, Dragonblight

Neutral: Dalaran

Blacksmithing skill 375-415
 
Make Reinforced Cobalt Set, you have to find the drop recipes listed below. These recipes are the cheapest to level

your Blacksmith from 375-415.

Make Reinforced Cobalt Shoulders Drop from Onslaught Mason

Make Reinforced Cobalt Helm Drop from Iron Rune-Shaper

Make Reinforced Cobalt Legplates Drop from Gundrak Savage

Make Reinforced Cobalt Chestpiece Drop from Venture Co. Excavator

OR if you can't find the drops, continue the list below.

Blacksmithing skill 375-385
Make Cobalt Gauntlets (5 x Cobolt Bar) 10

Blacksmithing skill 385-395
Make Sure-fire Shuriken (7 x Cobolt Bar) 10

Blacksmithing skill 390-400
Make Spiked Cobalt Belt (8 x Cobolt Bar) 10

Blacksmithing skill 400-410
Make Horned Cobalt Helm (8 x Cobolt Bar) 10

Blacksmithing skill 410-415
Make Tempered Saronite Bracers (13 x Saronite Bar) 5

Blacksmithing skill 415-420
Make Tempered Saronite Gauntlets (14 x Saronite Bar) 5

Blacksmithing skill 420-440
Make Savage Saronite Waistguard (12 x Saronite Bar, 1 x Eternal Water) 20

Blacksmithing skill 440-450
Make Titansteel Shield Wall (4 x Saronite Bar, 3 x Titansteel Bar, 1 x Frozen Orb) 10