The 4th Edition of "The Postcard Price Guide" is a 592 page work and is the most recent update of the series containing 900 illustrations (95% new to this edition). Completely updated with new values, it includes fifteen great chapters: Artist-Signed, Fantasy, Nudes, Publisher OPF, Santas, Greetings, Sets & Series, Advertising, Topicals, Transportation, Sports, Views (U.S. and Foreign), Real Photos, Roadside America, and Expositions. "The Postcard Price Guide" is the most comprehensive postcard price guide available. It lists thousands of prices representing millions of cards, both U.S. and Foreign, from 1893 through the modern era.
The pricing component here is, of course, useless except for the general sense of relative scarcity/value; for pricing, see ebay or a specialist dealer. Illustrations are limited, and only B&W. But nevertheless useful for its lists of series by publisher, which can be useful when you want to know how many cards might be in a series, what number ranges, etc. It's also useful as a general survey of the range of postcards, for beginners or for those with specialized interests who may be faced with a mass of cards from an album or box-lot.