One of the more useful tricks of the trade in WWW is to learn new and sensible ways (or even old and bad ways) of designing pages in HTML by looking at other peoples source. If you find a well designed page, use Mosaic (or other clients) to access the HTML source of the page, and (preferably) look at it side by side with the formatted page.
Beware, though, that if the page has been generated by a filter (see chapter 6) it may be weird and not terribly readable for humans!