Suggest a resource for standard beer style descriptions

Can anybody recommend a book that provides the standard descriptions/qualities for each kind of beer style? Is there such a book?

I know what I like, and what tastes good to me, and I generally know when I'm drinking a hefe, IPA, stout, etc without checking the label. But, I'm wondering if there are standards that describe each style and prevent someone from calling their "pale ale" an "IPA" or tell you when you have crossed the line between a "Belgian Dubbel" and a "Belgian Tripel"?

Is there a book or other resource somewhere I can turn to to learn the qualifying characteristics for each style of beer?

BJCP.org - Style Guidelines

These are the guidelines used by the BJCP (Beer Judge Certification Program). Any beer competition is judged according to these guidelines.

First off, the Bjcp Style guide goes into info on the major styles and includes lists of commercial beers of each style. http://www.bjcp.org/2008styles/catdex.php

And the book by Jamil and John Palmer, gives recipes for each style. http://www.amazon.com/dp/0937381926/?tag=skimlinks_replacement-20

Wow, quick replies, thanks!