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.
For instance, on the above sample page, my site is supposed to be about cats. However, other than the background graphics, theres nothing about cats that you can see quickly and clearly. Theres no content whatsoever that would draw searchers in.
Plus, search engine spiders, since they are textually based, cant see these images. I wouldnt blame anyone for leaving this sample site and looking for another one. Targeting your audience with the content they are looking for is paramount in order for searchers and search engine spiders to find you; in addition, your keyword-rich content will determine how highly you are ranked in the search engines (along with other factors).
A good rule of thumb to follow when determining how much content to include is to insert between 200-250 words of rich search engine friendly content on each of your site pages. More words are fine; just be mindful of the fact that users typically dont appreciate having to scroll down or read all the way across the screen. Break your content up in into columns, bulleted items, headlines, etc. (more on this in step 4).