****The Penguin Guide to Jazz on CD is my most used resource book. There are a handful of reviews there I strongly take issue with, but the batting average for the 10s of thousands of CDs is very high. Two guys have been doing the whole book, so there's a consistency in perspective you don't get in, say, The Rough Guide. The guys know there stuff, offer good insight and recommendations. It's also the most comprehensive I've seen, ranging from dixieland to avant, with a thorough listing of Euro musicians as well as American (the authors are British). Strongly recommended.