Search engine optimization (SEO) is the process of improving the volume or quality of traffic to a web site from search engines via "natural" or un-paid ("organic" or "algorithmic") search results as opposed to search engine marketing (SEM) which deals with paid inclusion.

Typically, the earlier (or higher) a site appears in the search results list, the more visitors it will receive from the search engine. SEO may target different kinds of search, including image search, local search, video search and industry-specific vertical search engines. This gives a web site web presence.

As an Internet marketing strategy, SEO considers how search engines work and what people search for. Optimizing a website primarily involves editing its content and HTML and associated coding to both increase its relevance to specific keywords and to remove barriers to the indexing activities of search engines.

The acronym "SEO" can also refer to "search engine optimizers," a term adopted by an industry of consultants who carry out optimization projects on behalf of clients, and by employees who perform SEO services in-house. Search engine optimizers may offer SEO as a stand-alone service or as a part of a broader marketing campaign. Because effective SEO may require changes to the HTML source code of a site, SEO tactics may be incorporated into web site development and design. The term "search engine friendly" may be used to describe web site designs, menus, content management systems, images, videos, shopping carts, and other elements that have been optimized for the purpose of search engine exposure.

I have comprised a list of sites that should be well known to anyone working in SEO / web design for 2009.

1. www.seomoz.org/blog – Great blog, great seo tools
2. www.searchengineland.com – Up-to-date search news
3. www.sphinn.com – social bookmarking for internet marketing
4. www.mixx.com – a friendly alternative to Digg
5. www.stumbleupon.com – One of the best social bookmarking sites
6. http://forums.digitalpoint.com – Webmasters forum
7. www.sitepoint.com – Another great webmasters forum
8. www.technorati.com – Promote your blog
9. www.mybloglog.com – A must have for blog communities
10. www.twitter.com – A great way to communicate with your audience
11. www.linkdiagnosis.com – A great link analysis tool
12. www.google.com/trends – See how trends in Google look
13. http://answers.yahoo.com – Great for providing traffic
14. www.sitemaps.org/protocol.php – Learn about sitemaps
15. www.ventio.se/seo-tools/google-position – Still in beta but good SE tool
16. www.wordtracker.com – Great keyword performance tool
17. www.seologic.com/webmaster-tools – Another source of good seo tools
18. www.backlinkwatch.com – Backlink analysis breakdown
19. www.avivadirectory.com/strongest-directories – Quality directories
20. www.internetmarketingninjas.com – Expert seo advise
21. www.wikia.com/wiki/Wikia – A wiki alternative
22. www.miniajax.com – Some great free Ajax scripts
23. www.sxc.hu/index.phtml – Free royalty free images
24. www.cssbeauty.com – CSS community
25. www.seounique.com/blog – Well I had to put my site in here!