Making a backup is very important especially for e-Commerce stores. You should back your site and database up regularly encase the unexpected happens. It’s also a good idea to back everything up before upgrading any major plugins or themes on your site. Below is a tutorial video about backing up your installation. There are also some good plugins out there that you can use to do this for you.
Backup Buddy is a premium plugin that takes the hassle out of backups.
Video by Adam Purcell of Hungry Dog Media