If you are addicted to knitting and love beautiful yarns, this is the book for you. It starts with around 30 pages of what I'd call the 'science' of wool, quite fascinating and presented in a very readable way. It then spends around 40 pages describing different breeds of sheep and the qualities of their wool, followed by a brief section on blending wool with other fibres.
The second half of the book is made up of patterns which show off the wools to best effect. They appeal to me because they include smaller projects, such as socks, scarves, hats and baby clothes, as well as sweaters, cardigans and shawls.
Although it is an American book, some of the yarns recommended for the patterns were sourced in the UK, or are available on the internet. Armed with knowledge gained from the text, it should also be fairly easy to find substitutions.
Not a book for a beginner maybe, but one that I hope will take my knitting to a higher level.