How Search Engines Work
In order to optimize your site for search engines ("SEO") it is important to understand how they work. These two papers describe the fundamentals of search engine operation.
Anatomy of a large scale hypertextual search engine
The PageRank Citation Ranking: Bringing Order to the Web.
There are some general principles that are straightforward to follow that will help your websites optimize their search engine rankings.
Remember that for the foreseeable future the only search engine that really matters is Google™. Optimize your site for Google ranking, and use your Google ranking to test your optimization - and everything else will follow.
Use the keyword in the Title
Make sure that the targeted search term or phrase is in the title of the web page. It is also important to have a unique title on each page.
Inbound Link Anchor Text
Anchor text is the text used in your linking structure, and is an important element of search engine optimization. The best way is to choose a descriptive domain name for your site, and by descriptively naming your sections and pages.
Link Popularity within the website
Make sure you create as many internal links pointing to the target page as is reasonable. Remember to use anchor text links within the content when applicable, to increase the link's value .
Inbound Links must be Relevant and Topical
Relevance matters: make sure there is a proper subject-specific relationship between the sites/pages linking to the target page and the target keyword. Make sure that the text on the page is relevant to the keyword phrases you are targetting.
Use the Keyword in the Body Text
Use the targeted search term in the visible text of the page. It is important to use the keyword phrase throughout the page where it makes sense. It is not just the targeted keyword phrase that counts, but the mix of all the words on the page that help to determine what the page is about - but don't cheat, and stuff the page with key-phrases out of context.
Don't Duplicate Title and Meta Tags on Many Pages
It is important to have a unique title on each page, and it is also important not to simply duplicate meta-tags across the entire site, as excessive duplication not only suppresses rankings, but it may also get your pages 'downgraded' to the search engine's 'supplemental results'.
Implement a sitemap xml file
This provides a list of pages within the site, together with hints about how important you feel each page is, when it was last updated and how often it changes. Learn how...
Google Webmaster Support
Google provide excellent webmaster support to assist you in optimizing your sites. The two most useful are: