Book recommendation: Modern Synthetic theory
There is no modern book of evolutionary biology that is not about the modern synthesis. So what you are looking for is just an introductory book to evolutionary biology.

I think the 2 most common introductory textbook to evolutionary biology are:


"Evolution: Making Sense of Life" by Carl Zimmer
"Evolution" by Futuyma


Note by the way that one can find recommendation on population genetics (subfield of evolution) here.