Wow, really didn't think this one would be as good as it is, considering the specificity and seeming dryness on a brief flip-through in the library, and the authors focus mainly on bilingual German-to-English dictionaries. You'll see alot of comparison back and forth between German and English, but it doesn't skew the discussion... it merely adds flavor.
Beautifully written, coherently (and obsessively, as befits the subject) organized, and an oddly excellent primer to lexicography in general. Covers standard monolingual dictionaries and their contents, 'e-dictionaries' (circa 2012), bilingual and learners dictionaries, and all the various things that go into properly designing them. Brief histories of major dictionaries, their innovations and feature changes over time, numerous comparisons between formats, and analysis on their influence and effectiveness to various groups of readers is all tied back to lexicographic theory.
Recommended for bibliophiles, language snobs, and meta-readers of all stripes. It's accessible, comprehensive, and well designed... all the things you want in a dictionary, or a book about them.