And since I was kind of in the mood for some dumbell rows tomorow I was kind of hoping this was going to be a good and motivational thread... I was mistaken.
Sorry man, it's just a very general area worked. If you were looking for scientific names of the muscles worked then just wait a bit and Im sure some expert will be here shortly to explain to you in great detail the dumbell row and it's mechanics. I say just start pullin the shit outta some heavy weight...with proper form of course. Then go eat.
http://www.theministryoffitness.com/mof/library/anims/oarows.htm There you go, quicktimes googled. And a more advanced mega-loaded with information site: http://www.exrx.net/WeightExercises/BackGeneral/DBBentOverRow.html Hey, I'm not going to do these on deadlift day anymore, but instead on Bench Press day. Having strong lats helps with a bigger bench.
Get a heavy dumbell, do a shitload of them, and then see what's sore tomorrow. It's really the best way to tell, no joke.