Seomoz have a must read document on Google ranking factors, each factor is listed with description, importance, disagreement, and what contributors have to say about that factor, and I have to mention that 37 contributors have given their opinion on this paper. Most important factors :
- Keyword Use in Title Tag (4.9)
- Link Popularity within the Site’s Internal Link Structure (4.1)
- Global Link Popularity of Site (4.5)
- Anchor Text of Inbound Link (4.4)
- Server is Often Inaccessible to Bots (3.8)
