Too many print editions throw in a few scattered Web site mentions and think that's enough. Overall, for a newspaper Web site to succeed, newspaper readers must know it's there. So sprinkle your paper liberally with mentions of the site and repeat the site's URL often. Also, make sure the URL is included in the editorial page masthead. Newspapers that have done this have documented rather large jumps in traffic when they list their URL prominently in print.
Page headers can contain page, date and, yes, the Web address.
Every reference to a Web site will go toward getting non-users to take the step and try out the Internet. Newspaper advertisements frequently include URLs, yet newspapers themselves are stingey in publishing them. It's quite curious. At the least, devote a small area on every front page to promoting the existence of the Web site. Some papers run a thin color bar at the top or bottom of every front page, including the URL and possibly a number to call to get newspaper-sponsored Internet access.