Resetting/formatting my G4 Bk

Hello everyone

I have just been given an old G4 mac book. It allows me to download various software updates but does not allow me to launch them, such as Skype and Safari. I am new to Mac and IT in general so any advice would be greatly appreciated. I have been told to basically reformat or reset whatever the terminology is the laptop. I have the CDs for installing mac book and the mac office so do you think i should do this?

IN the UK we have to pay like £30 pounds for an hour of help from Mac which is a total scam so i am hoping you will be able to help me.

Thanks