Dig a hole that is no deeper than the root ball so that the root ball rests on solid soil. Make the hole about twice as wide as the rootball. Set all trees and/or shrubs in the hole so that the top of the root ball is no more than 1" above the soil line with room on the sides for a mixture of peat humus, compost, or native soil. Do not add the mixture yet.
Untie burlap and roll it down away from the trunk and tuck in around the sides of the root ball. Some larger trees with come with a metal cage on the bottom. It is not necessary to remove this before planting. The top of the cage can be bent back and left in the hole and it will rot away in time. Carefully pull tiny feeding roots away from soil with a fork.
Place mixture of peat humus, compost, etc. around the sides of the root ball and pack it down so the mixture is just slightly above the soil line - it will settle.
Cover the soil with shredded bark extending out from the tree 16" all around. Pile the mulch to about 3-4" deep, then scrape the mulch back about 3" all around the trunk to form a "moat."
Planting 101 - How to Plant a Plant