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

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.

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

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

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

Check for broken links and correct 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 small.

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

Make sure your web server supports the If-Modified-Since HTTP header. This feature allows your web server to tell Google whether your content has changed since we last crawled your site. Supporting this feature saves you bandwidth and overhead.

Make use of the robots.txt file on your web server. This file tells crawlers which directories can or cannot be crawled.

Avoid hidden text or hidden links.

Don't employ cloaking or sneaky redirects.

Don't send automated queries to Google.

Don't load pages with irrelevant words.

Don't create multiple pages, sub domains, or domains with substantially duplicate content.

Avoid "doorway" pages created just for search engines, or other "cookie cutter" approaches such as affiliate programs with little or no original content.