The subject doesn’t really require enough info to fill a book. I would be highly suspicious of anyone trying to promote/sell a book on the subject.
For water for machines & boilers it’s pretty simple:
.Jim Schulman’s “insanely long water FAQ” is now 20 years old.
The SCAA had an online pamphlet from Zurich university on water, I think you have to pay for access nowadays.
La Marzocco have published a spec,
There is also the older SCAA water standard from 2012.
For brewed coffee things are much more wide ranging. So what are your intentions in terms of brewing, espresso etc.?
How are you intending to access/provide the water you finally choose (buy it, add minerals to DI water, filtration for your mains supply)?
The best place to start is to find out the characteristics of the water coming out of your tap in terms of total hardness and alkalinity as CaCO3 (these are the 2 most critical values), start with an in depth report from your water authority. It would be a great shame to waste time & money on books & articles if you have ideal water at the turn of a tap in your home, or a 5 minute fix for it.