You'll find the controls for optimizing your site for search engine traffic in the backend Configuration Panel. First, let's add some global keywords that characterize the site's content:
Navigate to System | Global Configuration. On the Site tab, there's a section called Metadata Settings.
Change the Global Site Metadata Description default text to a short summary of the content of your website. In our example, we'll enter CORBA is an international club of Collectors Of Really Bad Art.
In the Global Site Meta Keyword textbox, enter a few keywords that match the content of your website. Make sure to use the words and synonyms the visitor might use to search for your site's contents. You'll probably use a few words that are also part of the site description. In our example, we'll enter these keywords: bad art, ugly art, bad paintings. The Metadata Settings should now look similar to the following screenshot:
Click on Save & Close.