John C. Poppeliers

Not as interesting as guides to whole buildings, but if you need to remember what a quoin is, here's your ideal reference book. Nice, sort of pocket size, with great illustrations. Recommended for any architecture buff.

Short and plenty of images, this is a very good introduction to the american architecture. Its brevity is the good and bad side. More discussion in some buildings would be welcome, because their classification feels arbitraty and a better glossary with the terms in the text would be welcome. I needed to use a lot of wikipedia, which I enjoyed but somehow beat the purpose of book.

An excellent take-with-you guide to American architectural styles. Short descriptions describe the salient features of the style and numerous pictures give a good visual reference. In addition to using it in the field, it's also a good preliminary introduction to the topice