What sort of wireless router are you using?
If you want to share files in both directions, then both Macs should have file sharing turned on...
You can easily connect to the other computer then, through the finder Go menu/Connect to Server, or just command-K, and authenticate using the other computer's login.
It's not more complicated than that... and you can browse through the other user's files.
You might want to try a program called"Dropcopy".Should be able to find it at Macupdate.Takes all the hassle out of filesharing.I use it daily on my MBP and G4 IMac.
Well the iBook G4 will need something like SharePoints if you are running Tiger or Panther on it. This will let you point individual folders instead of the whole hard drive (10.4 or 10.3).
On your 10.6.x Mac Pro, does it have a wireless card installed?
Finally found the solution from Apple Discussions. All I needed to do was enable the Guest Account, and now my iBook G4 sees the MacPro!