Several factors influence the position of a site in the search results. They can be divided into external and internal ranking factors. Internal ranking factors are those that are controlled by website owners (text, layout, etc.) and external ranking factors are controlled by such things as inbound links. Just remember that 85% of traffic that comes to your website will be coming from search engines or web directories - this makes it an invaluable resource that must be used.
Always remember when you’re building a web site or developing page content make sure to build for both humans (you and I) and machines (Google, Yahoo etc.).