The "conventional" method is to split the pages into separate pages, or to provide a "back to top" anchor at the end of each section. You can also investigate "frames", but they don't work well with drop-down or pop-out menus.

Dani: nope, it won't scroll. That's why sites that implement these awful scrolling menus always have a "delayed reaction". The user scrolls, and then the menu catches up. It's event-driven, and requires Javascript. I think it's tacky in the extreme. I find myself trying to read the content, and then the menu appears over it, so I scroll a bit, the menu jumps around... bad.