When websites are created it is important to follow some basic rules to
help you optimize your site to appear on the first page of Google.
These rules that we should structure a site around are from, no other
than, Google themselves. 

From The Google Webmaster Guidelines:

** Make a site with a clear hierarchy and text links.
   Every page should be reachable from at least
   one static text link.

Our websites should be based on text links as stated above.
Each page should be accessible from each page

** Offer a site map to your users with links that point to
   the important parts of your site. If the site map is
   larger than 100 or so links, you may want to break
   the site map into separate pages.

Our websites should contain a sitemap.

** Create a useful, information-rich site, and write pages
   that clearly and accurately describe your content.

Our websites should offer "useful information-rich" content.
Furthermore ... our content must be unique and not found
elsewhere online.

** Think about the words users would type to find your pages,
   and make sure that your site actually includes
   those words within it.

Our website pages should be based on keyword phrases that people
use while searching (we have already addressed this issue).

** Try to use text instead of images to display
   important names, content, or links. The Google crawler
   doesn't recognize text contained in images.

Our websites should be based on text, images and fancy
elements are simply not needed.

** Make sure that your <title> elements and alt
   attributes are descriptive and accurate.

Our website pages should contain keyword phrases from our niche
research in the title tag.

** Check for broken links and correct HTML.

Our websites should not have broken links or html.

** If you decide to use dynamic pages
   (i.e., the URL contains a "?" character), be aware that not
   every search engine spider crawls dynamic pages as well
   as static pages. It helps to keep the parameters short and
   the number of them few.

Our websites should not be based on dynamic pages but rather
static page urls.

** Keep the links on a given page to a
   reasonable number (fewer than 100).

Our website pages should contain fewer than one hundred links
per page.

Structuring your site based on these "rules" from Google
will greatly improve your sites ability to rank in the search
engines.