So, asking a good friend, "Gee, how do I make dark iron bars..." he said something to the effect that it's a lot of trouble.
But, even though I have a few thousand better things to do, right here, right now, I'm going to go to Blackrock Depths and smelt some ore. Because that's kind of cool, that there's a special location to make these bars.
So, to that end: here is a fun site I came across: http://wow.crafterstome.com/home.html
4.2 Patch Recipes: http://kaliope.crafterstome.com/2011/06/patch-42-recipes-are-up.html
Comments and links to others that you've found useful are appreciated.
*bona fide: made in good faith, which nothing this young man did was in good faith.