DIYPloneStyle: Creating a Custom Style for Plone
This Link applies to: 1.2
This tutorial will teach you how DIYPloneStyle can be used as a base for creating a custom style product for Plone 2.1 or Plone 2.5 that adds to a portal a new skin selection and makes use of the new stylesheet and javascript registries.
Link: http://plone.org/documentation/tutorial/creating-custom-style