+1 on the Ezell book (arms and the man). Want to get it, but don't want to pay what I am seeing right now for it. The only defect with that book that I can think of is that it is kind of old (last edition was late-80s or early-90s, if I remember right), so a lot of the information that has come out since the Union broke up, especially relating to AK-74s and the AK-100 series, is missing from this book I would guess. This would probably lead to a few historical and technical statements, and assumptions that have since been proven wrong. Not sure though; I haven't had a chance to inspect Ezell's book in person yet. I would be interested in others' opinions of it.
(Edit): It looks like they have made a new version in 2001, but it is $$$
Chris McNabb (McNab?) also wrote one called "The AK-47."
Pretty good overview book, with lots of in-action pics and color schematics and etc, and is pretty wide-based (covers design, training, combat use, tactics which affected how the AK was used. etc). He only covers the military side of the house, however. Don't look for anything in-depth on any thing that is not specific to armies and whatnot. Also, it is an overview, not a detail-oriented book (mostly, although he does cover basic things like the 3 types of AK-47 recievers), so don't look to find super-detailed parts lists or cleaning operations or anything like that.
My two cents (or two paragraphs)