Content is basically includes what you see on the site: the text, graphics and even links to outside world. I would condemn using excessive graphics because they are not Search Engine Friendly plus users feel irritation when they get downloaded specially over a slow network.
Thousands of articles, books and forum entries detail how to make your site search engine friendly, but ultimately, one rule stands above the rest: Content is king. But I will say this rule is past now and I would like to say Unique, high-quality, unduplicated...