newbie- install to i-mac from usb

[chromaticwt zac]

hi,

I hope this is the correct mailing list for this question. I am a newbie.
I want to install FreeBSD 9.0 to an i-mac g3/g4 which doesn't have a
working cd drive.
I want to use a usb stick to do this. My question is what relevant doc
explains how to do this?
I searched google and could not find an answer that worked, even for NetBSD.
I tried issuing a dd command to cp the powerpc memstick image to usb, but I
can't figure out how to get
openfirmware to boot the usb. It is openfirmware version 3. I welcome any
help and/or suggestions.

Thanks,