Nice space, that's for sure. My wife treated me to an electrician who tapped the main box, ran about 50 feet of condult underground, back to a 60 amp sub panel. He used an 8 ft copper rod driven into the ground for the ground, then 3 12 gauge wires from new breakers in the old box. That makes 3 20 amp circuits. If you can dig your own trench, you can lay in the wires yourself. Needs to have a riser at each enad going into the old box, and at the other end, into the sub panel. The sub panel has breakers, then wires run to three boxes with 20 amp GFCI plugs.
IN your case, the sub panel can go inside, and feed the circuits in your shop.
Cost was $1500, including an extra circuit through the attic that runs our swamp cooler.
If you dig the trench, run the conduit, pull the wires and install the box yourself, you could probably do the job pretty easily and keep costs down. Have the electrician hook things up.
Pulling the wires through the conduit through 3 major bends was surprisingly easy. The electrician used a lite length of twine with a wad of plastic wrap on one end. He inserted it on one end then used a vacuum to suck it through to the other end. Then he tied a heavier rope (what HD has so you can tie your load down) onto the string and pulled it through. He tied and taped the twine to the 3 wires and pulled the wires through as I fed then into the conduit on the other end. Done is jig time! I think you can do all that mechanical stuff yourself and only have the electrician hook up the wires to the new breakers. We used full sized breakers but you can get the thin ones that you can put two in the existing panel.
110 v is pretty simple to hook up. I always use 12 gauge wire, 2 conductors and a ground, better to overdo it than hope lighter weight stuff will work. The cable from the subpanel outlets into the sheds is flexible conduit. Works quite well, and is now covered over by a small deck. The cables in the flex conduit are from 10 gauge braided wire extension cords. Simple
way to get from the sub panel into the shed.
After having watched the electrician do all this (he had a small ditch witch) in about half a day, I wouldn't hesitate for a moment to do the basic wiring in a shop like yours. The only part of my installation that was a bear was cutting through some massive roots left over from a big Cotton Wood.
You can find a book on wiring at Home Depot. Then hire an electrician just to hook it up and give it his blessing. The sub panel installation here didn't even require a permit.
For lights and a power outlet on the same circuit, you can buy wire with an extra (red) conductor. The on/off switch goes on the red wire. It is nice to have a power outlet over the work spaces.
I am wondering where you're going to put the table saw?
The more I do, the less I accomplish.