A couple of friends of mine recommended Bill Bryson as an author, and this is the first book I got my hands on. While breezy and interesting, I guess I hoped for something more cohesive. Essentially, each chapter is a self-contained essay, some of which are at best tangentially related to how English got the way it is (a chapter on wordplay, for instance, told me nothing I didn't know and seemed like an excuse for Bryson to list some beloved palindromes).
I found chapters that explained how much of our language came from Latin, Norman, German, Gaelic and native tribes of the Americas more interesting, and what fossils of ancient grammar or words we can still find lying in the exposed dirt, as it were (child->children, man->men and woman->women are some of the mere handfuls of words left in our language where pluralization comes in the typical German way. Court martial and attorney general come from the Normans, who learned to place adjectives after nouns, like the French).
Anyhow, worth a quick read, which it is.
This book is intended for laypeople, not for those with a background in linguistics. If you don't have any linguistic training, you'll probably find this an amusing read. If you are educated in linguistics, you might be too distracted by Bryson's few but glaring errors to thoroughly enjoy the book. Additionally, since the book was published in 1990, some of its information is out of date.
Bill Bryson discusses the history of the English language and explains many of the quirks and oddities (such as why "four" has a "u" but "forty" doesn't). It is not a grammar book, but a book about how English is used and misused.