Wine reference recommendations?

[ShortWiner]

I'm looking for recommendations for a good all-around reference book. I've got some novice books (i.e., Oz Clarke's "Introducing Wine"), but don't really consider myself a novice anymore; more like a novice-plus. At least, I could now use something more comprehensive. I'd like to be able to look up more obscure grapes or appellations, for example, and get an idea of what they're about. Any suggestions?