I have used SEOmoz for research into the wonderful world of SEO (aka search engine optimization), and I gotta say, I couldn't be happier. I can't say it's the best website for optimization out there, but I will say that it has helped me build a legitimately stronger version of Blogographer.
Here's an excerpt from the SEOmoz About page:
"Our goal is to have everything we create and cultivate - be it software, content, corporate culture, or professional relationships - live up to these tenets. We acknowledge that we are entirely responsible for SEOmoz's reputation; the level of success we achieve, the brand image we create, and the contributions we make to the marketing industry are a direct reflection of our ability to uphold the TAGFEE code."
Like what you see? Check out SEOmoz now!