Noob alert! - Dry milk question

Hi all-

I'm a noobie to the bread arts and I plan on displaying my ignorance, all in the hope of overcoming my usual forum (It's hell bein' stupid.) signature.  Keep in mind that my questions may not necessarily have a single answer and I'm probably not looking for a "right" or "wrong" answer. I'm looking for generalities. First up is a dry milk question.

I ocassionally come across a recipe that calls for a few tablespoons of non-fat dry milk powder. I'm under the impression that that particular recipe was created for bread machine use, but that isn't what I'm going to ask about. What does non-fat dry milk powder do exactly to a traditional loaf of bread? At the grocery, I can't seem to find non-fat dry milk powder (at least in a reasonable container size) and just recently stumbled upon Nestle's Nido whole milk powder. If I replace the non-fat with whole milk powder, what changes are likely to occur to my loaf of bread? I understand that I really can't replace dry milk with fresh milk in a recipe, but I'm curious as to what powdered milk "brings to the table" as an ingredient when baking a loaf of bread.

Any insight is much appreciated.

-s.w