Content is key in Web site optimization.

Content is the number one reason why visitors are looking for your site. If you make it difficult for the visitor to find you or your content, they will find someone else who will. Your content should fulfill a need for the visitor; whether this need is for information, merchandise or a service, and it should communicate it clearly.

Web Site Design Guidelines for a Search-Friendly Site

How do you make your site optimized for search engines? One thing to remember is that you're not only designing to appeal to your visitors, but also to the search engine spiders. There are a few principles to keep in mind while designing your site to be search engine friendly. These are just very basic principles.

• Make your text readable. Frantically busy backgrounds that obscure the text are not only hard to read but can make your site look unprofessional. Make your text readable: standard size (Web standard is 12), no silly fonts that have to be painstakingly interpreted, and make sure whatever font color you pick is readable as well (black is the preferred text color).
  
• Make your navigation clear. How many sites have you been to that give you the dreaded "page not found" error? This can be avoided by making your site hierarchy clear and consistent. Make sure that your navigation tools are obvious, and don't cloud them up with catchy titles. You'll also want to include a site map or index page for any site that's got more than 10 pages, just for clarity.
  
• Images. Even though I have an embarrassingly dorky graphic of a kitten waving and blinking,I don't dare put it on one of my websites, because it has nothing to do with what I'm writing. Every image on your site should be there for a good reason. Make images accessible for those searchers who might have their images turned off due to slow download times and give every image an "alt" label and a corresponding text link. Use graphics that won't give seizures as well; as in, no flashing, throbbing, or strobe lights.
  
• Overall Effect. While Flash is a great tool and I myself enjoy tinkering with it, it tends to increase download time. Make sure that whatever technologies you are using to spiff up your pages that they don't drag you down. In addition, be consistent with your site design. Make sure that every page in your site has some element that ties it in with the rest of the site; otherwise visitors can be confused by the conflicting design.
  

  The five basic rules of web design
  

  When designing a site you must focus on how you arrange words, images and multimedia files, she argues, and points to five basic rules of Web design:
  

  1. Sites should be easy to read
  Everything on your site should be easy to read. If not, people will hit the back button.
  

  2. Sites should be easy to navigate
  People are not always coming to your home page. So when they arrive at a page it must be easy for people to find what they are looking for.
  

  3. Pages should be easy to find
  Pages should be easy to find in search engines, directories or on industry related sites. People want to go directly to the page they search information for. If they do not land on the right page, they will search for it, but they ought to find it within 7 to 8 clicks.
  

  4. Sites should have consistent layout and design
  This applies to the use of white space, color etc. The users must be able to form a mental image of the site.
  

  5. Pages should be quick to download
  The majority of a page should download in 30 seconds or less using an old fashioned modem.