The whatis database is not set up on install. 'apropos' and 'whatis' does not work. Running 'makewhatis -w' fixes it. I know that it is called from cron.daily, but several hours can pass before that , and a new users needs this help in the first hours most !
This is intentional. We can't include a prebuild whatis database because we can't predict what man pages will be installed, and running makewhatis from the installer would just slow down the installation; cron does a better job here. If you have a better solution, let me know...
How about running makewhatis on first boot ? The calling script should then be deleted or altered, something like the Wind*ws RunOnce things :-)