First I should preface by saying that my Engineer is a Gnome and currently has 389 engineering skill on Live. So I can't really tell you what the first 14 points are going to look like. I *can* take an educated guess and say that you'll probably be making Hammer Picks and Overcharged Capacitors. Both of these items stay orange until 395, so they are good grinding recipes with minimal mats. I would encourage you to go with the capacitors, even though it requires a crystallized earth (basically, a mote). There's a quest that requires a capacitor, I haven't run into it myself but I've heard people begging for them in chat. I'm guessing capacitors will be a decent money maker as a result.
When you hit 390 skill, that's a good time to make any flexweave/spynocular toys you're eyeing. You may as well get a skill point if you're going to want them anyway. At 395 I switched to the Froststeel Tube, since I intended to make guns later in the progression. Unfortunately Blizzard patched in a few new items after I started down this road and I ended up abandoning the guns in favor of another item with lower mats. So you can either make tubes or the Bladed Pickaxe is a relatively cheap item that stays orange until 400. Instead of making guns I switched to the Diamond-cut Refractor Scope because it had lower mats and I thought it might be a better seller. From 400-410 I alternated between the tube and the scope, making a couple of tubes and then using the tubes to make scopes.
At 410 you'll have another opportunity to make a few more toys, the recipes you learn at 400 skill will remain orange until 415. Once you've depleted the fun stuff, you can start cranking out Saronite Bombs which are learned at 405 skill. They stay orange until 425 so you can focus on these for awhile. You could also craft Saronite Arrows or Bullet Machines until 425, this is totally up to you. I didn't do that because the number of saronite bars required for the ammunition was higher than the bombs (6 bars vs 12).
When you hit 425 you can start making goodies like the Sun Scope or MOLL-E. If you're Goblin like I am, you can also make super-cheap Global Thermal Sapper Charges for 1 saronite bar and 1 volatile trigger (3 cobalt bars for 2 triggers). The ammunition and potion injectors are also an option beyond 425, they are all still orange. You also get a couple of new toys: a Gnomish Lightning Generator and the Gnomish X-Ray Specs. Personally I think the mat costs on both of these items is on the high side, but that's just me. Six titanium bars (IE: khorium) and 2 shards for a novelty head pieces seems steep. The Lightning trinket needs 4 Primals and 2 titanium bars for a use-only effect, which also seems a bit much. Maybe I should submit some feedback on that....
Anyway, that's all I have for now on Engineering, I'll continue posting updates as I work closer to 450.