The LSU Ag Center talks about mulch. LSU Ag Center and Mulch
I know from planting many trees it is important to mulch properly. It makes a big difference in the life of a tree, especially in the early stages. Mulch retains moisture, and feeds the tree overtime. A big mistake I see a lot is the mulch is piled high around the base and trunk, looking similar to a volcano with the tree in the center. This is not good. Water runs off the piled mulch and never gets to the roots. The mulch must be spread evenly out to the drip edge of the tree, therefor acting as a retention basin for water falling from the tree itself. Now is a good time to plant trees, early spring before they really get a chance to wake up.
Good luck any green thumbs out there.