I’ve been reading The History of English, by Scott Shay. It’s definitely scholarly, but I find it easy enough to follow, and I don’t have any particular expertise in linguistics … other than I are speaking English all in my life.
Perhaps it’s more limited in scope than what you’re looking for but I found David Crystal’s The English Language very enjoyable. However, I must point out that when I read it in the early 90’s, I thought that some of the studies he referenced were old (dating from the 50’s or 60’s). Still, it contained lots of valuable and sometimes funny information. What’s more, I think there’s a new edition.
That’s a good point. People think of language history as something that’s old and settled. As with all other sciences, though, we’ve probably learned more in the past 50 years than in all previous history combined. Modern computer searching is revolutionizing the field, and that’s just begun the transformation.
A number of books mentioned here are older. I liked Peter Farb’s Word Play a lot, but it dates from 1973. For the most part it’ll hold up if all you want is an entertaining introduction. But when he talks about pidgins, or the Sapir-Whorf Hypothesis, or the origins of language, just as examples, much of what he writes is outdated.
David Crystal seems to write a big fat book on English once a year. The English Language was first published in 1987. The Stories of English is from 2004. The Cambridge Encyclopedia of Language has a 2010 updating. It’s a very cool book, designed for the popular reader, heavily illustrated, and fascinating on every page.