Hello Carolyn,
I live not too far from you (outside Norwood), so we have a similar climate and likely similar soil. We planted a number of fruit trees 4 years ago, apples, pears, peaches and plums and have added a few more things in since then. We didn't do much to ammend the soil beforehand, that may have been a good idea, but I guess I subscribe to the philosophy of the best time to plant a tree is yesterday, failing that , today!
Since planting, I build fairly sizeable mulch rings around the trees. These vary abit in their makeup as I use materials that I have to hand. Typically a lot of dried leaves, weeds that I have pulled out. If I've been splitting wood down in the forest, or have moved brush piles, I will add wood chips and bits of decaying twigs and wood, as I clean up. We also have a number of comfrey plants around the food forest (which the pollinators love) and I will chop these down and add to the mulch piles. My aim is to have comfrey near every tree, as I notice that I'm lazy, and the trees closer to the comfrey plants receive mulch more regularly!
In terms of general ground cover, we had a lot of disturbance to the soil after we built our swim pond and we've seeded white clover in those areas, just to act a ground cover and add nitrogen.
As yet we have only harvested peaches from the trees, maybe if we'd ammeneded the soil prior to planting, things would have established more quickly but things are growing. I think we would have had plums this year if the ice storm hadn't done quite so much damage to our plum tree.
Good luck with your journey. Enjoy it!
Richard