Different Linux distros have different method to set the hostname. On Fedora Linux, it is quite simple.

Open the /etc/sysconfig/network file

vim /etc/sysconfig/network

Find the line starting with

HOSTNAME=

Assign the hostname for this computer to this variable. For example, to set the hostname to ericpc.fclose.com, just set

HOSTNAME=ericpc.fclose.com

Save the file and it should take effect. If the machine uses the network service, restarting the network may be needed:

# service network restart