To find a good SEO it must have
Design
All content including links, headers, alternative image text, alternative frame text and content text on a well designed website is viewable to the user and, more importantly, in terms of SEO, the web crawler.
User Friendliness
Everything the viewer wants to know on your site should be no more than three clicks away. In terms of SEO, a web crawler can only see the pages on your site that are directly linked, so a well optimized site will have text links as well as any graphical links such as flash or java script.
Content
As well as the body content of your site, a web crawler will also look at the page title, page description, keywords, and file name. It will make its judgments on how to list your site based on these factors. A well-optimized site will have a page title that briefly describes the content, a description tag that will describe the content in more detail, keyword tags that will pull select keywords and key terms from the content, a file name that reflects the page title and content that is clear and relevant to the user and the web crawler.
More About Content
The biggest mistake most people/companies make when optimizing a site is overdoing it, i.e., repeating keywords, duplicating image tags, flooding the backend with descriptive code and trying to fit as many keywords/terms into the meta tabs as possible. Not only is this a messy practice. but it can also get your site penalized and may be dropped from searches altogether. When building/optimizing a site, the first person you should be thinking of is the user and not the web crawler. Not only will this be better for your SEO efforts, it will also be a better experience for your potential customer.