As far as I'm concerned, any part of the canning process that can be done outside, should be done outside. I had my son wash the peaches outside, then carry them in using a big plastic tub. One side note is that if you leave picked peaches or apricots out in the sun for more than a day or two, they will develop sunburn spots that turn hard and won't peel well.
I had the kids take turns blanching the peaches for a minute or two in boiling water, then transfer them to a sink filled with ice water. Blanching serves 2 purposes: first it allows the skin to slip off the peach and second, it stops some of the enzymatic process of oxidative browning. You can sort of see our assembly line. The blanched peaches cooled in the cold water then were peeled over the next sink, then I sliced them and cut out any bad spots prior to placing them in the jars.
Would it have been quicker to peel them myself? Sure, but nothing beats hands-on experience.
They really liked peeling the peaches once they discovered how easily the skins slipped off. Yes, this led to fighting over who got to be the main peeler . . . so we started making rotations so they could take turns at different jobs.
I kept a bowl handy with a little Fruit Fresh (you can use lemon juice) into which I would slice up the really beat-up, ugly looking peaches. Once I was finished canning, these went into freezer bags for future use in smoothies, cobblers, etc. I slid the peach halves cut side down using that handy flat plastic slide thing (poking out of the half-filled jar). Also, for my liquid, I went for an extra light syrup using 5 cups water and 1 cup sugar. I popped this into the microwave until the sugar dissolved, then poured into filled jars until an inch from the top. The most vital part of the process, is making sure that your jars are wiped clean on the top surface. Use a clean cloth and wash it out regularly during your canning adventure. The key to a good seal is a clean top surface of your jar.
Yes, my cute Dad came over with another canner and his camp stove to speed up the processing time. Otherwise I just turn on the burner unit on the side of my grill and use that to process my jars. It takes longer than the stove-top, but it is less messy and keeps your house infinitely cooler!
I ended up with 24 quarts canned and 15 quart freezer bags of peaches. So talk your kids through the process whether it is canning peaches or making freezer jam. The more you make the effort to involve and teach them, the better your grandkids will eat!