The fact that such files and directories aren't on your Mac may simply indicate that you skipped the "BSD subsystem" part of the Mac OS X install process.
Therefore, you may want to perform a custom install by using your Mac OS X install CDs ( or the Restore CDs that came with your iBook ) to install this component only. Then, re-run the latest Mac OS X "combo" updater available for your installation to make sure that it is up-to-date.
I wouldn't recommend copying these files from another installation since this may be the symptom of a larger issue.
Let me know if this helps !