How do I create a backup world? I want to have a backup of my entire server so if it gets griefed I can reset it.
you have the original world that you use, and the copied worlds that you don't touch and just let sit somewhere in your computer. If someone does grief the world, you go to the copied world, and replace the griefed world with the copied one. Of course, you lose all changes to the map since that copy was made. So, don't take a backup once a month, and complain when someone griefs your server 29 days later, the day before you backup again about losing a month's worth of time.
Either every few days or week. I honestly use a plugin to backup every 24 hours just so one is always made if I get busy or forget.