Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
You could just read the bazillion other threads here asking this same Linux on PowerPC question.
 
i would max out the ram...install new harddrive...install osx leopard

ive done the whole ibook linux thing before...and went back to tiger.
 
I tend to agree with Tom. If Linux is your main goal here, you can sell the PowerBook and buy a much more suitable machine. Tiger or Leopard are far better for PPC Macs.
 
I have personally run Ubuntu 10.10 and Kubuntu 10.10 on two PPC machines, a PowerMac G4 quicksilver and an iBook G4 1.33ghz, the latter of the two can run Ubuntu okay but not great. Kubuntu boots on the iBook but the effects are slow (it's like watching it load each frame haha) but they do work. The PowerMac could only boot Ubuntu and it was also okay, but not good. Tiger runs way better on both. If you really want Linux on a Mac, I recommend either an older version that came out about the same time as your computer, or a new Intel Mac.
 
Ubuntu and all its derivatives aren't a good choice for PPC. They're slow and their support is incomplete. For a faster, supported alternative, use Debian or MintPPC. The only time I'd hesitate to recommend Linux is if you have an Nvidia graphics card. The PPC drivers are third party and not good. ATI drivers are much better (incidentally, it's the opposite on Intel installs--Nvidia drivers are much better than ATI).

I have a hand-me-down iBook G3 / 256 MB RAM that dual boots Debian (gnome-core and Openbox) and Mac OS 9, and it's great for running the latest office and web software, and the OS 9 partition is used as a really cool retro gaming platform.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.