The /etc/dhcpd.conf file is the place to be. Edit it with Vim on the command line, but if you don't trust yourself make a copy of the original file first. Copy it back if changing it with Vim fails for whatever reason. The cp routine should be fairly foul proof
Add something like this to /etc/dhcpd.conf:
hardware ethernet 00:35:14:8E:C3:8F;
linux.local.lan must have it's IP number in the /etc/hosts file on the server, otherwise use numbers in the dhcpd.conf file.