I grew up in a family that built homes. My father is an architect. I worked a bunch of different construction jobs in college. I was "trained" in a trial by fire, essentially cut loose with plans and told not to fuck up.
My father drew the plans and provided funding, I did everything else. Fortunately, I built a long way from his offices so he would rarely drive up to my housing additions. When I moved closer to the offices his micromanaging was actually the thing that caused me to quit, even more so than the refusal to split money more fairly.
My step brother found a better partner and my father tried to fuck him over as best he could. The problem was the same for him though, once he had my step brother doing 97% of the work, he had no leverage over the subs anymore as most of them were found and hired by my step brother. Dad was just an asshole that would come around and bitch once in a while.
My step brother is fantastic at it. He's far better than both my father and me. If I'd liked building homes more than building software I'm sure I'd have stuck with it longer (well I did it for about a decade). The problem is home building can be feast or famine. You have to have enough capital to live through the booms and busts.
When you're building, you have to know everything, because subs will (not always but more than you'd like) try to cut corners or do shit not to the plan/bid. Finding good subs isn't too hard, the key is making sure they understand how you operate. Written bids, following building codes (at a minimum), and getting good quality work means baby sitting.
Essentially that was my job. That being said, the better you are at managing waste and baby sitting, the higher your margin and the more quickly you can complete projects.
I was the building supervisor, but also the run and get shit so the crew isn't waiting on a delivery, also the salesman (yay weekends for no extra money!), and everything else that would pop up.
I saw a book in Lowes once that was actually really good on how to build your own home. It had way more info than was needed for where I've built (less restrictions here). Wish I'd at least kept the name so I could recommend it.
Essentially you trust your subs, but you make sure what they're doing is to code and spec. I used to go and unlock houses at 5:30 am, go to my normal job after that. Drive by at lunch and make sure everything was okay at 11am (get anything necessary, make any calls, etc.). Go back to work. Go by house at 5:30pm to lock up, then drive home. If I had a spec house available to sell, I'd unlock it at lunch and lock it at 5:30 as well. I sat on my houses on weekends in addition to that.
So 14 hour days M-F 6-8 hour days on the weekend. I also had a software startup I was doing on the side. So I'd be programming while sitting on the houses when there was no traffic.
I did this for about 7 years with all 3 jobs. Easily 90-100 hours a week away from my evil first wife (most my motivation, lol).