...and search engines into each "theme" or "section" of the site. Content Body content, meta content, and graphicalcontent tells search engines and users about your service or product. How you deliver that content can influence both users...
http://searchenginewatch.com/3632663
...Include how-to's, generalist information, news (use Blog software), video, photos and maps. Tag all graphicalcontent with keyword terms Write naturally, stay on a single topic per page. Forget keyword density, it is overrated...
http://www.seobook.com/seo-strategy