No book is going to help because as Munger said "there is no formula I can give you".
The best approach is what @DooDiligence suggested, i.e. case studies. Look at some of the best investors' deals and their rationale, try to understand what they saw and how it played out. Importantly, focus on the business dynamics not consensus views.
Buffett has written extensively about valuation, remember that multiples are just the inverse of discount rates.
No approach is equal. Buffett, Munger, Ackman, Rochon, Howley, John Huber are all worth studying but in the end, YOU must do the work.
Start practicing and with time you'll get better and understand what works for you.
It is more art than science.
Best,
G