You will first need to be logged into your clientarea here.
Log in to manage your account
Click the ACTIVE button to the right of the domain name
1. Click the Backup Icon from your Clientarea
2. Click "Download a Full Website Backup"
3. Generate a Full Backup
4. Click the "Go Back" button
5. Download your backup to a safe place
You will need this backup and the file in it - keep them in a safe place on your computer. You will not be able to restore your site with this backup but it contains all your images and the database file.
Video on how to Backup your site http://www.merchantmoms.com/index.php?m=tutorial_viewer&seriesID=17&videoID=190
All Cpanel Videos http://merchantmoms.com/knowledgebase.php?action=displayarticle&id=1119