Essential reading for anybody working with websites or specifically working with on-line marketing and SEO.
SEOmoz - Search Engine Ranking Factors 2009
"Every two years, SEOmoz surveys top SEO experts in the field worldwide on their opinions of the algorithmic elements that comprise search engine rankings."
"Each participant was asked to rate more than 100 search ranking factors along with specific questions about hot issues in the SEO field. This document, representing the collective wisdom of expert practitioners, is, in opinion, one of the most useful resources for SEO practitioners of all varieties, helping to provide transparency into what matters (and doesn’t) for best practices in search engine optimization."