Drupal Global Theme Settings
To work with the Drupal global theme settings, log in as administrator and click (you guessed it) the Appearance link on the Dashboard menu bar. When Appearance overlay opens, click the Settings tab found at the top right of the overlay. Notice the list of themes, as well as the words Global Settings. These are all the currently enabled themes. Global Settings will be opened by default.
The theme settings let you choose
Elements, such as how many columns or rows, that will appear on the site.
User information that appears in various content sections.
Whether the default Drupal logo appears.
You can select to use an alternative logo here: Just deselect the Use the Default Logo check box. Doing so opens the options that you use to link to an online image or upload an image file to your Drupal installation.
A favicon, that small shortcut icon that appears in the URL address bar in users' browsers when they visit your site. The default favicon is a tiny Drupal logo.