SeoMoz put out their bi-annual report on what it has found to be the top search engine ranking factors. This report has A LOT of information in it, and is sure to help everyone with seo.

I have attached a few graphs. The first 2 are summary graphs. The first displays the data that was found on current search engine trends for ranking positions. The second is called "Future of Search" and its what seomoz is predicting will be more or less important in future rankings.

The third attachment shows what they found as far as your domain name choice - this correlation pretty much confirms that a keyword match .com domain is superior to a keyword match .net, and both are superior to a keyword filled domain or subdomain.

The forth attachment shows how social networks have impacted search results. There's also a section on how links affect your rank, as well as keyword agnostics and how keywords on pages plus placement of those words impact serps.

The full report is here: http://www.seomoz.org/article/search-ranking-factors