You can follow the instructions in the mini-HOWTO for setting up the NIS
server and clients.  The rc.autofs and rc.nis scripts can be placed in
/etc/rc.d and called from rc.local.  They simplify the process of enabling
the NIS+automount stuff at boot time.

If you do decide to use the rc scripts, copy them to /etc/rc.d and edit
rc.nis.  Modify the top appropriate to the system it's on.  Edit rc.local
and add a line to call "/etc/rc.d/rc.nis".  You do not need to add a line
to call rc.autofs, it's called by rc.nis.