After building your website, the next goal is to attract users and traffic to your site. While this can be done using advertising, there are some aspects of your website that you control that can help your website become more search engine friendly which will make your website rank higher in the search results.
Google will treat URLs that are prefixed with www and URLs that are not prefixed as different pages. This distinction has the effect of diluting your pagerank.
Choose one or the other, and use mod_rewrite to automatically redirect the browser.
"meta" tags should go inside the "head" tag of a HTML document. They are not displayed on the page, but are used by search engines.
This is shown in as part of the search results in a search engine.
<meta name="description" content="This description will appear in search engine results, but is not visible on the page itself">
This is a comma separated list of keywords related to your page.
<meta name="keywords" content="html,programming,meta,seo">
Spider readable sitemaps can be generated for a website. e.g. see http://magicmonster.com/sitemap.xml for a simple sitemap.
http://magicmonster.com/robots.txt can specify where the sitemap can be found.