Exploring Wine by Steven Kolpan, Brian H. Smith and Michael A. Weiss. Three professors tell you how to study wine the way their students at the Culinary Institute of America do ($60).
The Little Book of Bordeaux Wines by Bruno Boidron. A small volume on first-growth Bordeaux (and lots of lesser châteaus) for fans with limited shelf space ($12).
The New Sotheby's Wine Encyclopedia by Tom Stevenson. The third edition (revised and updated) of the authoritative world-covering (and map-studded) reference work ($50).