Why use a style sheet?
Standards require use.
Provides users with flexibility to create and view with their own custom style sheets.

Using a cascading style sheet allows the developer to set the color, size, font, and placement of text for all its pages. Altering the style sheet allows the developer to change the look and feel of the website without having to edit each page individually. Users can also develop customized style sheets to their own preferences, such as larger font size or different text or background color.   Keep in mind that many users are still using browsers that do not support style sheets.  Ensure that documents work with or without style sheets to ensure access to all users.

Content Management Systems such as Blackboard and WebCT provides features to change the course navigational style via menus and icons.

Method:
<link rel="stylesheet" href="scc.css" type="text/css">

Testing Tools for Style Sheets
-- CSS Zen Garden
-- Federal Court Concepts
-- Turn off style sheets in browser
-- Use text-only browser
-- Test using validator