On October 2, 2012, Google announced updates to their Webmaster Quality Guidelines. The update consists of a reorganization and expansion of the basic quality guidelines and many more specific articles; ex. quality and technical guidelines for rich snippets.
We reviewed the Google Webmaster Guidelines and compiled a list of 10 best practices we already deploy and think you should too:
1. Think about what makes your website unique, valuable, or engaging. Make your website stand out from others in your field.
2. Think about the words users would type to find your pages, and make sure that your site actually includes those words within it.
3. Create a useful, information-rich site, and write pages that clearly and accurately describe your content.
4. Make pages primarily for users, not for search engines.
5. Avoid tricks intended to improve search engine rankings.
6. Make a site with a clear hierarchy and text links. Every page should be reachable from at least one static text link.
7. Make sure that your <title> elements and ALT attributes are descriptive and accurate.
8. Make use of the robots.txt file on your web server. This file tells crawlers which directories can or cannot be crawled.
9. Submit an XML Sitemap using Google Webmaster Tools. Google uses your Sitemap to learn about the structure of your site and to increase our coverage of your webpages.
10. Mark up your content for schema.org
For additional information, review Google Webmaster Guidelines.