To backup your website, or parts of it (Home Directory, MySQL etc) first log in to your cPanel:
Once logged in, in the middle of the page click on Backups
Here we can perform either Full Backups or Partial Backups/Restores. It is a good idea to initially take both a Full Backup, as well as the Partial Backups. A Full Backup is useful as a complete backup archive of your website, email and MySQL.
Please note: a Full Backup can not be restored by you the user. It can only be restored by support but is still useful as it is a complete copy of your site, and the file can be unzipped so you have a copy of all your home directory files, MySQL databases and email accounts.
Before, and after you make changes to your website it is a good idea to perform Partial Backups of both your Home Directory and MySQL Databases. Partial Backups produce zip files that you can easily upload and restore at anytime through cPanel.
Performing a Full Backup
To perform a Full Backup, under Full Backup click on Download or Generate a Full Web Site Backup
Leave the Backup Destination set to Home Directory.
Enter an email address if you wish, to let you know when the backup is finished and ready for you to download.
Click Generate Backup
On the following page click on Go Back to take you back to the downloads page. If you entered an email address you should receive an email stating the backup is complete within a few minutes. Larger sites may take a little longer.
Once you have received the email, go back to cPanel and reload the Full Backup page. You should now see a link to a backup file under Backups Available for Download
Click on the backup file link to download the file to your computer.
Performing a Partial Backup
To perform Partial Backups on the Backups Page, click on the Home Directory button under Download a Home Directory Backup to download a zip file to your computer containing your home directory. This file can then easily uploaded and restored by you at a later date if needed.
If you have MySQL databases you should download a backup by clicking on each database name under Download a MySQL Database Backup. You can also do the same for your email forwarders and email filters if you wish.
Restoring Partial Backups
To restore a Home Directory backup file you have on your computer, on the Backups page, under Restore a Home Directory Backup, click on Choose file.
A window will pop up and you can find and select the home directory backup file, it will have a filename similair to backup-yourdomain.com-3-3-2011.tar.gz. Then clickUpload. Once you click on the Upload button it will pop up a new window and the restore process will start.
Use the same method as above for restoring MySQL Databases, Email Forwarders orEmail Filters if you have copies of these partial backups on your computer.
For more details about cPanel backups you can visit the official cPanel site:http://etwiki.cpanel.net/twiki/bin/view/AllDocumentation/CpanelDocs/BackUps