“Walk into the public library in Danbury, Connecticut, and you’ll find the usual shelves stacked with books, organized into neat rows. Works of fiction are grouped alphabetically by the author’s last name. Nonfiction titles are placed into their propper Dewey Decimal categories just like they are at tens of thousands of other libraries in North America.

But visit the Danbury Library’s online catalog, and you’ll find something rather unlike a typical library.

“A search for The Catcher in the Rye bring sup not just a call number but also a list of related books and tags—keywords such as “adolescence,” “angst,” “coming of age,” and “New York”—that describe J. D. Salinger’s classic novel … Click the tag “angst,” and you’ll find a list of angsty titles such as The Bell Jar, The Stranger, and The Virgin Suicides.”

So begins Gene Smith’s newly released book Tagging: People-Powered Metadata for the Social Web (New Riders). That’s right. The first book dedicated to tagging begins with LibraryThing—specifically our LibraryThing for Libraries project!

Library 2.0 people pause a second. How about that: a book about new developments in social media starts by talking about new things going on in a library? Not a social networking site, not a photo sharing site. A dream come true.

That’s all I have to say for now. I knew the book was coming; Gene interviewed me for it (selections on page 134). But I haven’t finished it yet.

My first impression is that it’s rich and detailed, covering everything from what tagging is and why it matters, to how to implement it at the level of user interface and even technically. But But, as is my wont, I’m already scribbling little objections and expansions in the margins. That’s the sign of a good book, right?

I’ve created a discussion group on Talk for people reading the book. Come join me to talk about it.