There are many more factors that go into how the search engines rank a page. These are just a few and they are the easiest for those who are new to SEO to understand. I left out complicated terms such as LSI and the VIPS.(Thanks Gypsy) Incoming Links anchor Text This is the top ranking factor. You can see evidence of this as President Bush's official biography is number one for the term "miserable failure" even though the term does not appear on the page. This was the result of a Google bomb where a large number of internet users linked to the biography using miserable failure as the anchor text. The anchor text is the text you use to link to another website. An example is seo rant. Seo rant is the anchor text because it is the actualy text that you click to move to the next page
Keyword Use in Document Text The amount of time your keyword appears on the page is very important. I usually stick to about 5% of total text on the page.
Title Tag This is referring to the title of your webpage, found in between the tags. All of your website's pages should have unique titles. This is one of the main reason some web pages fall into the supplemental results.
Reputation and Subject of linking sites. It is very important to get incoming links from reputable sites that are related to the topic of your site. While you can't control which sites link to you, links from unrelated pages does nothing to enhance your pages position in the SERPs (Search Engine Results Pages)
Accessibility of Document This one is pretty straightforward, They cannot rank a page if they cannot find it. Make sure all pages on your site are reachable from at least one static text link. Submit a sitemap with the Google sitemaps program which can also provide you with a lot of useful information.
External Links Link to sites related to yours and never link to bad sites. Porn, gambling and sites that install spyware are the main culprits. Don't links to sites that use shady SEO tactics or one's that have been banned by the Search Engines.
Outbound links They lend weight to a document with the Search Engines. Try to ocassionaly quote an outside source and put a link to it.. You will make friends and increase the page strength at the same time
Primary Subject Matter of Site The primary subject matter of your site.
Internal Site Links The internal linking structure of a site can greatly impact SEO. Use a consistent linking structure, keep important pages one level down from the home pages and use important keywords on internal links.
Link Popularity of Site The number of pages linking to yours.
Uniqueness of Text How unique is your text compared to all the other sites? Text that is copied from other sites will never rank well. So please do the web a favor and use unique content.
Age Factor What's the age of the domain and the page? Older sites have more trust with the Search Engines.
Competition This is the number one SEO ranking factor, even though most of the time we do not place enough emphasis on it. Your competition has a lot to do with how you are ranked. Target keywords that have less competition and are easier to conquer. Then after your site has some reputation then you can target more general keywords.