Within the Account Admin section, go to the Customize Logo & Title page.
Enter the title to be displayed under you logo at the top of the page. Below, upload a JPG version of your logo. Click "Apply Changes" to complete these settings.
NOTE: The logo and title settings will appear for that Sub-Account and any below it. Apply these settings at the top level to set them for your whole account.
Logo & Title Restrictions: The maximum size for logos is 300x200 and must be in jpg or png formats. If the logo image is too large it will be resized to fit the page. The title section has a maximum character length of 255.