It depends on your level. If 40+ and have your mount I would suggest going to the badlands and running around the outer portion of the map. This is by far the easiest way to get iron that I know of... also the easiest way to get mithril. If you're lower level, the charred vale in stone tallon mountains and 1k needles are good places to look. However, for pure iron and mithril badlands can't be touched. I did a mining run the other night w/ my hunter (at level 60 so I can probably do it faster than you can) in the badlands. After an hour and 15min of mining and killing whelplings hoping for a little pet... I pulled in 75 mithril, about a dozen truesilver, 15 gold, 52 iron, and like 3 silver. I personally use the "gatherer" mod that shows all the node spawns on your map after you mine them, and let me tell you that map is covered in iron/mith nodes... just have to be able to get to them... and that requires lvl 40+ ... really 45+ is best for quick runs.