First make sure you have dhcp installed, the RPM has both client and server. Use, as su, /usr/sbin/setup, then select services, make sure that dhcp is selected so that it will run at start up. Next you need to use linuxconf. Select Control Files and Systems, then select Configure Linuxconf modules, from here make sure you select DHCP, select any other services that you may want to configure from linuxconf while you are at it.
You will have to exit linuxconf and restart it, now you will have a menu item for DHCP. From there configuring DHCP is a cinch. Just fill in the blanks basically.
Regards,
Paul