From Catalogablog:

"The October/November 2007 issue of the Bulletin of the American Society for Information Science and Technology includes a special section on Folksonomies.

* Introduction: Folksonomies and Image Tagging: Seeing the Future? by Diane Neal, Guest Editor
* Why Are They Tagging, and Why Do We Want Them To? by P. Jason Morrison
* Trouble in Paradise: Conflict Management and Resolution in Social Classification Environments by Chris Landbeck
* Image Indexing: How Can I Find a Nice Pair of Italian Shoes? by Elaine Ménard
* Flickr Image Tagging: Patterns Made Visible by Joan Beaudoin"

Overview of tagging

A bibliography for the Feb. 2008 South Eastern Pennsylvania Theological Library Association (SEPTLA) workshop

From catalogablog: 

Smith, Tiffany (2007) Cataloging and You: Measuring the Efficacy of a Folksonomy for Subject Analysis. In Lussky, Joan, Eds. Proceedings 18th Workshop of the American Society for Information Science and Technology Special Interest Group in Classification Research, Milwaukee, Wisconsin.

Interesting read

Nice summary of tagging.  Include bibliography