Guidance on Style Guides: Lessons Learned
http://www.stcsig.org/usability/newsletter/0104-style.html

Wilson, Chauncey E.
Usability Interface

Abstract:

This article highlights some of the lessons that I’ve learned about the process of creating style guides and implementing processes for ensuring that a product is consistent in a number of dimensions. I discuss the purposes and benefits of a style guide, a process for creating a style guide, the many types of consistency, reasons why style guides fail, methods for ensuring consistency, and some references that discuss these issues in more detail.