Here's a good and basic review. Short, but communicates what you would want to know as a summary.
http://spartanideas.msu.edu/2014/05/08/nicholas-wade-interview-a-troublesome-inheritance/
As the writer points out, the first half of the book contains good information that will be surprising only if you haven't followed human genome research over the last 10 years. Yet among social scientists, you will still hear nonsense about "social construct" and such -- this remains the default view of the AAA, APA, economists, etc. Those arguments were rendered laughable years ago as the genome became sequenced and subjected to mathematical analysis, but people still routinely embarrass themselves by trotting these pious mantras out. That pseudoscience is really the main target that Wade is aiming his book at.
From a 2010 article in Science, here's how the actual clustering of human genetic variation breaks down in a mathematical model:
But human genetic variation and its clustering is just part of the story; some kinds of variation matter much more than others. In fact a single gene can kill the organism outright if it varies one way or another. Other gene variation does nothing whatsoever. So one wants to know how the variation is structured, but also WHY it is structured that way, and what the effects of the variant genes are.
Most important (and one of the bitterest controversies) was whether the genetic variation was actively selected for in different ways between groups, rather than just random drift. In other words, whether it was actively evolving in response to environment. Yet again, prevailing social scientific consensus (please note that this had no relation to actual scientific consensus) was that human evolution stopped in that sense from 100,000-60,000 years again. But again, that was a testable hypothesis. These arguments have relatively recently been slaughtered on the altar of mathematics and modern genome sequencing, which allowed us to analyze the degree to which given variation was the result of selective pressure. As it turns out, about 8% of the total variation between groups seems to have been recently "selected" for, or more straightforwardly, evolved differently.
What we still DON'T know, however, is what that selective pressure actually was for the vast majority of the genes. In other words, while we can generally tell with math that specific genes were selected against others in a given population, we can't necessarily tell why, or what that gene's effects are, or how it was selected (why it became more common). For example, much of that selection may reflect things like the need for different disease/parasite resistance in different environments. It would actually be very surprising if jamming people together into urban cities crammed with livestock did not have a radical selective effect for reasons of disease resistance alone. Disease resistant genetics may not strike people as very important, but in terms of reproductive survival when you drastically change the environment, it's ungodly important. Disease resistant genes can become dominant with incredible speed in societies stricken by plagues.
It's also important not to get too hung up on gene numbers, since even a handful of genes can have significant effects on many different phenotypical traits.
But that's the first half of the book. Again, if you have been following research in this area over the last decade, none of it will be new, nor is it really controversial. If you have been blindly suckling at the teat of social science, on the other hand, it might surprise you.
In any event, the second half of Wade's book consists of speculation -- by his own admission -- on that subject of what genes were selected and how they relate to regional human history and culture. This is the part where he loses the interest of most, including me. This is why even those who enjoy watching Wade mock the reigning social scientific pieties have slagged on his speculations and described his book as very uneven.