This book is definitely for experienced knitters and those with a real interest in the science behind the way socks work and the best wools to use with it. The first 50 pages are teaching you all about wool - written in a very accessible way. Being an avid knitter I found this very interesting, but I can imagine some people would just want patterns to knit without all the know-how. Also the author is American and so there are a few "translations" required for English knitters - but nothing any experienced knitter won't have come across before.
I found the patterns very exciting - some of them quite a challenge but very satisfying when done - much more so than the plain socks I had been knitting. Needle sizes are given in U.S. and in mm, but yarn is in American weighting, so again, some translation required. This is easily worked out by the needle size required and then doing a tension square, so don't let it put you off what is a fabulous book for sock-knitting fans, giving the confidence to reach out beyond the normal run-of-the-mill patterns!
An added bonus is that the socks look beautiful to wear, and would make a special present for someone.