Before you touch a spade, before you touch a shovel, before you put anything in the ground, look around. The number one mistake with tree planting is putting it in the wrong location. So many times I see trees planted, below power lines, too close to the house, too close to another tree or right over the sewer lines. So site selection is the number one important thing for a successful planting and avoids the need to either move the tree or destroy it later.
Know the plant specifications of the tree you have chosen. Knowing this information makes it easier to pick a proper spot. Once your spot is chosen you can then grab that shovel or spade. And if it's a big ball and burlap tree grab the young neighbor boys while you're at it. Tell them that there is pizza and drinks in it for them. It's important to dig the hole to the correct depth. What I do, is I stand my spade up to the ball or pot and measure how tall it is. That way I don't make the young boys dig too much. You need to plant to make sure the ball is not exposed.
Once you have your hole dug, get the tree in position. If it's in a plastic pot or container you can either cut the container out from around it or pull the plant from the container. If it's ball and burlap it is very important to make sure to cut all the twine and rope off the ball. If you don't feel comfortable taking the burlap off loosen it from the top and when you place the ball in the hole, push the burlap down the sides as far as you can.
Now those great wire baskets that they put around balled trees have to be taken off. We cut them off before we put the tree in the hole. Slide the tree in the hole. Be careful not to break the ball. Add a couple bags of compost in with the tree. Now before backfilling, this is one of the next most important things. Get your wife and ask her if it's straight. If it looks crooked then you're off the hook.
Once you backfill then water in. I like to make a well around the tree and put a hose on it at a slow trickle and leave it run for a few hours. If the tree needs any kind of support you can either stake it or put on supports. For tree supports, you can use wire with piece of old hose to protect the trunk or you can buy nylon tree supports. Hammer in stakes at an angle about 3' from the trunk. Use three per tree. Make sure all three are tight. You may have to go back and adjust later. Once the tree is rooted in and stable make sure you take off the supports so it does not girdle the trunk and kill the tree.
Now sit back and crack a cold one and enjoy the new greenery in your yard. In a few years it may offer you some shade.