iBook not loading

A friend of mine has given me her iBook G4 in the hopes that I could get it up and running. When we try to start it up, we get a little world icon blinking at us. And then it turns into a folder with a picture of the OS (blue face) and a question mark flashing back and forth. Nothing else.

I did look this up, but didn't see something that matched with it exactly.

Thank you for the quick reply. I've tried what it says, and am thinking I might need different discs. I'll try again later, but all I got was a screen of code.