See following sites for navigation menus:
CSS Library Horizontal CSS Menus: http://www.dynamicdrive.com/style/csslibrary/category/C1/
http://www.dynamicdrive.com/dynamicindex1/
http://www.cssplay.co.uk/menus/
How to Style an Unordered List with CSS: http://www.webreference.com/programming/css_style2/index.html
How To:
http://www.w3.org/TR/WCAG10-HTML-TECHS/#links
http://www.creativepro.com/article/dreamweaver-how-create-you-are-here-navigation-links
http://efuse.com/Design/navigation.html
Simple JQuery Accordion menu: http://www.i-marco.nl/weblog/jquery-accordion-menu/
Drop-Down Menus, Horizontal Style: http://www.alistapart.com/articles/horizdropdowns/
The Right Way to Make a Dropdown Menu: http://www.sitepoint.com/blogs/2009/04/01/the-right-way-to-make-a-dropdown-menu/
Ron