Are you looking for a book that will explain basics like water hookups, electrical systems, and so on?
Or are you looking for more like a "home repair book" for RVs?
I looked for a while when I started and didn't really find anything that I felt actually provided guidance in specifics. They were all very general and tended to gloss over areas where I wanted more info.
I ended up going out with the attitude that if it broke during the trip, i'd just do without and fix it when I got home. I did that several times over the years:
Fridge thermocouple died - had a friend bring me ice (or I would have gone for some) and used a soft-sided cooler I kept for day trips.
Hot water tank split - used a couple pitchers I had for lemonade and used the campground water.
Battery died - used puck lights and lanterns, the campground water, and the campground restrooms. Fridge doesn't need 12v to run.
Found that having camped before, finding myself with a broken house system didn't ruin a trip, just made it different.
Would still love to find a book that explains the systems enough for quick repairs on the go, so hoping someone actually responds with some titles.