Reposted from forums to public by request:

Okay. I decided to pick up engineering, Here's the guide that I created last night, trying to spend the least amount of gold I could. I must admit that it's about 70 gold for EVERYthing, But in the end, you'll have like 20-25 gold in your pocket. This is the Quick and Dirty way. If you can't keep up with the bill, I suggest getting mining, as it alleviates nearly 90% of your costs when you just straight mine to 300.
First is the shopping list of all items I used in my powerlevel. You WILL have leftovers on most things but I padded for the unlucky.
Next is the List itself. What to skill up on until the level desired. For instance, 1-40 means stop doing it when you get your 40th profession point. Next, what typically you can do with the item. Then, AHed ingredients and finally the ingredients in ONE make of the crafted item.

Also, please leave comments.

----------------------------------------------------------------
Shopping list of items needed:

90 Rough Stones (AH)
80 Coarse Stones(AH)
70 Heavy Stones(AH)
60 Solid Stones(AH)
50 Dense Stones(AH)
10 Wooden Stock (EVend)
29 Weak Flux (EVend)
50 Heavy Leather(AH)
10 Wool Cloth (AH)
33 Runecloth(AH)
51 Copper Bars(AH)
10 Silver Bars(AH)
55 Bronze Bars(AH)
15(*19) Iron Bars(AH)
*4 Coal (EVend)
4 Steel Bars (*get a blacksmith to make from iron and coal, MUCH cheaper.)
106 Mithril Bars *cringes, sorry.*(AH)
159 Thorium Bars *runs*(AH)
----------------------------------------------------------------

Engineering trainers are usually found in major cities.
Artisan engineers can be found in Orgrimmar and Ironforge.
The single master engineer (for all engineers) can be found in Gadgetzan in Tanaris. His name is
Buzzek Bracketswing.

----------------------------------------------------------------

Level: Name of Skill, approx to keep. Keep more in case. [how many to buy from AH.] (recipe req. for each.)

0: Buy a Blacksmith hammer.
Buy Schematic: Green/Blue/Red Firework (Fireworks Merchant in Booty Buy/Iron Forge/Orgrimmar) 40s
Buy Schematic: Thorium Widget - Engineering Supplies in Orgrimmar/Ironforge 1g
Buy Schematic: Thorium Tube - Engineering Supplies in Winterspring (Everlook) 1g40s
1-40: Rough Blasting Powder, sell all [90 Rough Stones] (1xRough Stone)
41-50: Handful of Copper Bolt, used for 66-75.[10 Copper Bars] (1xCopper Bar)
[b]51:Arclite Spanner
[6xCopper Bar](6xCopper Bar)
52-65: Copper Tubes, 10 used for 66-75.
[35 Copper Bars] (2x Copper Bar 1x Weak Flux)
66-75: Rough Boom Sticks, sell all (
[](1x Copper Tube 1x Handful of Copper Bolts 1x Wooden Stock)
76-95: Coarse Blasting Powder, keep 20 for 121-125.
[80 Coarse Stones] (1x Coarse Stone)
96-105: Silver Contacts, Keep 5 for 146-150, Keep 5 for 191-195.
[10 Silver Bars](1x Silver Bar)
106-120: Bronze Tubes, sell all.
[30 Bronze Bars](2x Bronze Bar 1x Weak Flux)
121-125: Small Bronze Bombs, sell all.
[10 Bronze Bars, 10 Wool Cloth]
(1x wool cloth 1x silver contact 4x coarse blasting powder 2x bronze bar)
126-145: Heavy Blasting Powder, 10 for 146-150, 50 for 150-175, 15 for 191-195.
[70 Heavy Stones] (1x Heavy Stone)
146-150: Big Bronze Bombs, throw at friends or sell.
[15 Bronze Bars]
(2x Heavy Blasting Powder 3x Bronze Bar 1x Silver Contact)
150-175: Blue, Green or Red Fireworks, sell.
[50 Heavy Leather]
(1x Heavy Leather 1x Heavy Blasting Powder)
176: Gyromatic Micro-Adjustor
[4x Steel Bars](4x Steel Bar)
177-190: Solid Blasting Powder, 10:206-210, 15:211-225, 16:236-245, 10:246-250
[66 Solid Stones](2x Solid Stone)
191-195: Big Iron Bomb, sell
[15 Iron Bars]
(3x Iron Bar 3x Heavy Blasting Powder 1x Silver Contact)
196-205: Mithril Tubes, sell.
[30 Mithril Bars](3x Mithril Bar)
206-210: Unstable Triggers, 10 for 236-245.
[10 Mithril Bars, 10 Solid Blasting Powder]
(1x Mithril Bar 1x Mageweave Cloth 1x Solid Blasting Powder)(need for later)
211-225: Hi-Impact Mithril Slugs, sell on AH for good profit
[15 Mithril Bars, 15 Solid Blasting Powder]
(1x Mithril Bar 1x Solid Blasting Powder)

---From here, the going will be dangerous, you may want to stock 5-10 more of each thing I've listed in case of TERRIBLE steaks of luck, as you will be flying out to Gadgetzan. Also see my section below about Goblin/Gnome engineering. That is an expensive way to level, and my FAQ is cheapest without having to make a choice.---

226-235: Mithril Casings, 10 for 236-245.
[40 Mithril Bars] (3x Mithril Bar)
236-245: Hi-Explosive Bomb, sell.
[10 Mithril Casings, 10 Solid Blasting Powder]
(2x Mithril Casings 1x Unstable Trigger 2x Solid Blasting Powder)
246-250: Mithril Gyro-Shot, sell.
[16 Mithril Bars, 16 Solid Blasting Powder]
(2x Mithril Bar 2x Solid Blasting Powder)
251-260: Dense Blasting Powder, Keep all for shells!!
[50 Dense Stones](2x Dense Stone)
261-290: Thorium Widget, keep for most high-end stuff or sell.
[99 Thorium Bars, 33 runecloth] (3x Thorium Bar 1x Runecloth)
290-300: Thorium Tubes, keep for most high-end stuff or sell.
[60 Thorium Bars] (6x Thorium Bar)
---When all is said and done, it should have taken you 3-5 hours to get it all made. Grats.---

----------------------------------------------------------------
Pick up Schematics that help out:

"Discombulator Ray":
1.You need a DELTA ACCESS security card. It's a low % drop in gnomeregan, so getting it is the hardest part. I've found 3 off of the mobs coming from the back door. You can also find it from AH though in some cases. The important part about delta security card is that it is not BoP, so once you have gotten your schematic, sell it to someone else.
2. You must have 160 engineering.
3. Learn the schematic directly from 3500-D terminals on the way to Thermaplugg from the back door, in the engineering labs.
*4. Now, I have heard also that Alliance need to have the Red Access card, as well, but I did not have it when I got the ability.

"Schematics: Repair bot 74A":
Learn this from a scroll on the ground next to Golem Lord Argelmach in BRD at 300 engineering. (First of all, you'll need the Shadowforge Key.
1. Take your first left, unlock the gate, run up to the gate on the right, unlock that, run up to the door on the left, unlock it.
2. Walk up to the big gear in this room, and unlock the chain.
3. Run up the ramp in this room, take the left up the stairs, then follow the hallways. You'll come to a room with about 4 fire elementals, stairs going down on the left, and a ramp going down on the right. Go right.
4. Ahead of you will be many non-elite gnomes and elite elementals standing around. Go straight down from the ramp until you come to a room with a named, and two elementals guarding him.
5. The plans are to your right.)
It takes 12 Thorium Bars, 4 Rugged Leather, 1 Fused Wiring, 2 Elemental Earth, and 1 Elemental Fire. It has only 1 charge before it is expended. Not cheap.

----------------------------------------------------------------
---Types of Artisan Engineering---

The Master Gnome engineer is in Booty Bay.
The Master Goblin engineer is in Gadgetzan. These trainers will give you a task to complete to join
that society. Note that you don't need to choose either, as it is not linked to learning
artisan engineering at level 35 at all.

For your Goblin engineering quest:
20 Big Iron Bombs (190) (3x Iron Bar 3x Heavy Blasting Powder 1x Silver Contact)
20 Solid Dynamite (175) (1x Solid Blasting Powder 1x Silk Cloth)
5 Explosive Sheep (150)
(1x Bronze Framework 1x Whirring Bronze Gizmo 2x Heavy Blasting Powder 2x Wool Cloth)

For your Gnome engineering quest:
6 Mithril Tubes (195) (3x Mithril Bar)
1 Accurate Scope (180) (1x Bronze Tube 1x Jade 1x Citrine)
2 Advanced Target Dummies (185)
(1x Iron Strut 1x Bronze Framework 1x Gyrochronatom 4x Heavy Leather)

Goblin is the realm of BOOM. You get a wider variety of and more powerful explosives. Unfortunately the dragon gun and the mortar still trigger the shared explosive reuse timer, though they are on seperate cooldowns.

Goblin engineering produces the following:
1) (205) Goblin mining hat (AC 190, +15 sta, +5 mining, mail armor, BoP) (You no take candle!)
2) (205) Goblin construction hat (AC 44, +15 fire resist, cloth, BoP) Use: absorb 300 to 500 fire damage for 1 minute.
3) (205) Goblin sapper charge (explosive, limited use) Damage enemies around you for a lot while damaging you
for slightly less.
4) (205) Goblin Rocket Fuel recipe (creates a recipe) create recipes for alchemists, who in turn can supply you
with goblin rocket fuel, necessary for some schematics.
5) (205) Goblin Mortar (explosive, 6 uses) Has a minimum and maximum range. Binds on equip, so you can
recharge your own mortar (using the Mortar: Reloaded schematic gained at the same time) for significantly
fewer resources than a new mortar, but cannot recharge anyone elses as it is soulbound to them.
Also worth noting is that this item apparently still causes a "stun" effect instead of a "disorient" effect,
which is somewhat more useful. However, the radius is smaller than listed, probably 6 yards instead of 10.
6) (225) Goblin Rocket Boots (AC 41, cloth) These boots are one of the few items usable by those without
the engineering skill. They allow fast running for a short period of time, but are prone to explosion.
7) (230) Goblin Bomb Dispenser (trinket, BoP) Can create one bomb that behaves as an exploding sheep, every
30 minutes.
(235) The Big One (explosive, 2 uses) A massive bomb that deals high damage in a huge radius. Has a
longer than usual activation time.
9) (240) Goblin Dragon Gun (trinket, BoP) A 10-second channel creates a cone of flame that deals damage each second.
10(?)) (245) Goblin Rocket Helmet (AC 50, +15 sta, cloth) Allows you to charge an enemy, knocking it unconscious
for 30 seconds and yourself for less time. Damage ends the effect.

Gnomish is the realm of devices. Trinkets for every occasion. If you are satisfied with the amount of explosives from standard engineering, go gnomish for utility.

Gnomish engineering produces the following:
1) (205) Gnomish Shrink Ray (trinket) temporarily reduces target's attack power by 250. this can also backfire
on the user, causing them to shrink or grow.
2) (205) Inlaid mithril cylinder plans (creates a recipe) creates plans for blacksmiths, who in turn can
provide you with mithril cylinders, necessary for some schematics.
3) (210) Gnomish Goggles (AC 45, +9 agi, +9 sta, +9 spi, cloth, BoP) goggles with agility
4) (210) Gnomish Net-O-Matic Projector (trinket) Roots target for 10 seconds, 10 minute cooldown. Can backfire
and root the user instead.
5) (215) Gnomish Harm Prevention belt (AC 66, +6 sta, leather) Use: blocks 500 damage over the next minute,
but can also temporarily remove the user from reality.
6) (225) Gnomish rocket boots (AC 41, cloth) requires engineering to use, but cannot be destroyed like the
goblin version.
7) (230) Gnomish Battle Chicken (trinket, BoP) summons a combat chicken for 90 seconds. 30 minute cooldown.
(235) Gnomish mind control cap (AC 50, +14 spi, cloth) allows mind control of your target for a short time.
9) (240) Gnomish death ray (trinket, BoP) a 4-second channel deals damage to you each second, and then releases
more than the total amount at your target. Aggros as you start channeling.


Those are the big differences I know of. It's purely a matter of preference. Keep in mind that aside from the ones that are Bind of Pickup, you can trade/buy to get most of the other's products!