Mac Os X Upgrade?


I have a copy of Mac OS X Panther, and I currently have no OS on my ibook. I can't get this install to go through? Is this version just an upgrade and do I need to buy a full setup version some where? If so which one would you recommend?
What does the writing on the CD or DVD say and where do you have the disk from? Did it come with a previous Mac? I recommend to buy a full setup version of panther. Take a look at ebay. I am sure you will find many appropriate offers.
If you have a G4 ibook, go for tiger.