Stick to HTML, CSS, Javascript and the DOM.

You could design all the pages of your site, using HTML and CSS, and then pull in each page using AJAX, so the browser doesn't have to reload. But if the user has Javascript disabled, they can navigate each page seperately.

Another alternative is to have div blocks with each section's content, all in one HTML page. Then use Javascript to hide the blocks when the DOM is ready, and display each one when it is called with a link. Again, if Javascript is disabled, the user can just browse the entire page, scrolling down for each section.