First, on the subject of linguistics, is A Mouthful of Air by Anthony Burgess (of A Clockwork Orange fame). I'm still working on it, but there's one thing I found really interesting; the notion that nearly all Americans use the dark |ł| rather than a bright |l|, even at the beginnings of words like "lily." Apparently we all use the dark |ł| as in "dull." I tried it, and I did find a slightly different tongue position for the bright |l|, but then again, I have been mistaken for a Brit (maybe I sound like I've had RP, I dunno).
The other book, on the subject of the UK, is Notes from a Small Island, by Bill Bryson. Sort of a travelogue of England, Ireland, Scotland, and all the other -lands. I've always felt sort of an odd kinship with the Brits, and occasionally find myself muttering "Mustn't grumble," to myself (moreso after having read the book, but still...)
At any rate, I highly recommend both of them, one for some interesting examples of linguistic stuff, and one for funny descriptions of your country of residence.