Backing up my the Public Directory of my Website into my Home Directory...

I'm building a Wikisite, and I would like to set-up regular back-ups of the public directory into the home directory of my website. Therefore moving the data from a publicly accessible area into an protected area. To allow content to be restored in case of cyber vandalism. I'm good at programming in PHP and Javascript, but unfortunately that's about the height of my abilities. Javascript obviously isn't going to help with this. And I'm thinking PHP probably won't help either. I'm willing to learn though. I thought maybe it would be some sort of Linux commands on the actual server but I'm really not certain. Anyone have any ideas?