I'm always happy to help!
Now, I'm not sure exactly what you mean about iptables for a DHCP server. You need to install a DHCP server separately. For Debian, you would do the following:
# apt-get update && apt-get install dhcp3-server
if your not using Debian.... then you should be!
And then I believe the config files are in '/etc/dhcp3'... but I have very minimal experience with that.