Found a baby Mourning Dove, what should I do?

I found a baby Mourning Dove on the ground behind a tree at my house. And don't say I should leave it alone and wait for its parents to come. Because another bird was behind the tree too, dead with feathers everywhere. So now I'm trying to take care of it. And I don't know how to feed it. Most of the time I use tweezers because well...there black and I figure it would think of it as its Mom. But instead it tries to shove its beak all the way to the back. And...on top of all that its wing is broken...and it looks REALLY bad. It looks separated from its other half. Will the wing heal? And how long does it take for one to mature? And how should I feed it and what should I feed it?