If there is a (or are) social bookmarking site that deals explicitly with your niche and has an active community, I suggest hitting that up often with new stories. Helps spread the word about your site among people who are likely to be interested in the topic it relates to.
Well......you need not to submit a site again and again.......but you should submit your different webpages timt to time but don't try to submit same page twice..........
Good point coolsko, social bookmark sites are a great place to do gain backlinks to "deep" urls/internal urls