Survey your space to plant in. A deeply shaded spot at the bottom of the lowest part of your yard, with higher ground/buildings surrounding it may not be the best place for trees.
A spot where air flow slopes away from your tree is a better siting. Trees like sun too.
As you dig your hole what is the dirt like down there? if its sandy and the nearest peice of limesone outcrop is five miles away a little crushed limestone, and some bark mulch or finished compost (less than 20% by volume) couldn't hurt.
If the soil is full of clay rough up the sides of the hole before you refill it. A smooth sided hole can create a bowl trapping roots and water

. Again only finished compost or bark mulch as amendments.
Know that your trees are going to be fed not by fertilizers but by mutualism between the tree and mushroom family organisms.
As you refill your hole with tree in place check and keep the old soil line of the tree at its new soil line.
When your all done and soil is compacted back around the tree. Water it in really well. Add a layer of more bark mulch at least as thick as the second knuckle on your finger. Water it well too. (that bark mulch is going to feed the mushrooms that feed your tree).
I do prune new trees. leave at least 3/4 of the sapling that was shipped to you. If leaves have already erupted leave some on.
Standard rootstock (apple) trees need 25 feet of space between trees. Semidwarf (apple) and peach need 12 feet or more between trees.
Plan on watering your trees every day it does not rain till fall.
I use pretty substantial stakes. Not so much to stand tree up but to act as warning for mowers...