How would you integrate several different stylesheets into a website?

As you're probably aware, a style sheet defines how the pages will appear within a website. Since style sheets have a great deal of overhead and require individual HTTP requests, developers often seek to minimize the number that they use. While one is ideal, many developers prefer two; one for the front end and one for the site's administrative side. Even so, you should be able to describe how you integrate several style sheets, assuming that this is the current practice the organization you are interviewing with uses.