100Keywords.com Offers two free online tools for websites, but both are very useful. The first, a Keyword Research Tool provides valuable information about which terms people search for each month and how many times the keyword is requested, and the second, a Keyword Density Tool shows how well your website is designed for the search engines.
LinkingMatters.com A free resource that helps web site owners, managers and consultants to run an effective linking strategy. The site offers an online linking strategy report, articles and linking resources. Definitely worth a visit.
SEOBook.com A good site to visit if you're looking for the latest search engine news. Check out the archives for past news.
URLTrends.com URLTrends.com is a new site that provides a host of useful facts about any URL such as Pagerank, Alexa rank, Incoming Google, Yahoo, MSN and Alexa links, overall incoming and outgoing links and much more.
Li'l Engine A site totally devoted to search engine optimization and site promotion. If you're looking for useful information on these topics, we recommend a visit to this attractive resource.
SocialPatterns.com A personal site by search engine marketing expert, Michael Nguyen, which mainly consists of search engine news and search engine marketing discussion. Interesting content.
Search Engine Showdown An online compendium of search engine facts, analysis, information, and comparisons. If you want some quick insight into the major engines, this is a good starting point.
Google Alert Runs daily Google searches for you and emails you whenever new results appear. Keep track of what the web is saying about you, your websites, your competitors or just about anything else you can think of.
Search Engine Friendly Layouts Website provides standards compliant layouts with clean and functional markup. Useful for webmasters and search engine optimization specialists.
Traffick.com Charts developments in the world of search engines, focusing on the business angle and how search engine marketing is evolving on the Web. The content is primarily articles related to the SE industry arranged in 5 major categories.