Click on the page you would like to optimize and you should see an SEO tab beside the HTML tab at the top. If you don't see the SEO tab then it means you have not entered key words or key phrases yet. Click here to enter your key phrases.
On this page example, I have chosen to optimize it for "Computer maintenance package".
When you click on the SEO tab for the page, it will display and highlight your key words and key phrases. It will tell you if the page is Bad, Good, Very good for the key phrases you have targetted.
Search engines love content so keep writing more content on your page to include your key phrases. The more you have the better chance you have at rising to the top of the search engine results.
Keep working on your content until you see "Very Good!" for all the areas that need improvement.