Microsoft made dramatic improvements in the Quick Launch menu navigation with the option for end users to create sections, add manual links and have folder contents automatically listed in the menu. This is a screen shot of the MOSS menu navigation administration which allows multi level navigation for the top menu strip.

WSS only allows for single level navigation. If you want to add menu items for web part pages that live in a document library, you would have to add the page urn's to the menu by hand.
For WSS users, my poor man's web page publishing solutions consists of a WSS Document Library which contains Web Part Pages that uses the Content Editor Web Part to allow the authoring of content and a navigation component that groups the pages by a topic. The pages are automatically displayed in the menu if the yes/no publishing column is Yes.
The first step in creating the menu navigation for this site is to create the library that will hold the Web Part Pages. You can see my pages library here http://www.wssdemo.com/pages (I have deliberately not used the built in publishing feature of a SharePoint list so that you can see that there are a lot more pages in the library than displayed in the menu.
This is a standard Document Library with the default template set to be "Web Part Pages" and some additional metadata columns for the page title, choice field for menu grouping, tool tip text field and publishing flag Yes/No field (You could use the built in content approval option instead).
After creating a few pages in the library, you can create a web part page and add the list view web part for your pages library to the page. By editing the view to filter on the published flag and group by the menu value you can get something that looks like the web part below.