Planting: Fall is a good time to plant saplings (maples or other native species), but it should be done after the sapling goes into dormancy, exhibited by losing its leaves. Fall planting should only be done with containerized stock. Bare root stock will have a much lower survival rate when planted in the fall.
After planting the dormant sapling, remove the summer’s dead twigs and place a thin layer of mulch around the base of the tree. Only water the tree if the soil or root ball appears to be dry. Do not soak or fertilize the sapling.
Mulch: Check around the base of the tree. If there is no mulch, add a thin layer of mulch (leaves, wood chips, or other mulch from your local retail nursery) to protect the tree and reduce evaporation. Do not “volcano” the mulch into a pile around the base, this will encourage rotting at the base of the tree.