Breadcrumbs are a form of website navigation that keep track on the path followed by a website visitor. They are sequential links telling the user the location of the page within the website (example: category / subcategory / sub-sub subcategory / product).
Here is a list of tutorials that will give you an idea of how you can setup a CSS based breadcrumb on your site:
Simple scalable CSS based breadcrumbs
CSS Breadcrumbs from Dynamic Drive
Create apple.com-like breadcrumb using simple CSS
CSS Design: Taming Lists – Breadcrumb trails
