if you want to play around with PPC then take a look at
http://www.ppczone.org/forums/index.php site, you will find lots of devs and users there that can help with all things PPC including many PPC linux OS etc.
you dont need to worry about wireless printing as its exactly the same as wired ip printing, as long as the sending machine is connected over tcp/IP wired or wireless it will work with any currectly set wired tcp/IP printer.
you dont say what make/model printer you want ot use or their inbuilt connections usb/par/ser/ip ? what are they.
Easy Way:
you might like to look for a linux livecd for the x86 that already has tcp/ip printing setup,iv never looked for such a thing but you can be sure one of the livecd's will have it nearly all setup to boot and go.
http://search.ntlworld.com/ntlworld/.../ip%20printing
http://search.ntlworld.com/ntlworld/...ip+printing&cr=
http://www.slax.org/forum/viewtopic....=tcp++printing
http://www.slax.org/forum/viewtopic....=tcp++printing
out of interest, whats the spec of the G4 1gig? in your average machine, how much ram?.
Ubuntu PPC with a USB DVB-T stick works very well for streaming vlc multicast content over the network for instance.