First of all, you have to decide what species of the tree you want to plant and if it is suitable for your landscape. Other factors to be considered are: type of soil and its pH, luminosity, humidity, and the substrate, etc.
Make sure that the roots and the hole you make for planting are in the right proportion; also be sure that the tree will be planted at a proper depth. The hole has to be usually twice bigger than the root ball. Spring and fall is the best time for planting.
But if you want a professional team to help you out, Amiral Service Inc is ready to guide you through the process of planting a tree.