Search Engine Watch is the authoritative guide to search engine marketing (SEM) and search engine optimization (SEO), offering the latest news about search engines.
http://searchenginewatch.com/

Everything you ever wanted to know about your site listing in the Google search engine.
http://www.google.com/support/webmasters/

The leading global search engine marketing event, conference, training and expo series covering search engine optimization (SEO), paid search advertising, social media, link building, keyword research, duplicate content, usability & more.
http://www.searchenginestrategies.com/