Your exports file can be as simple as:
Code:
/directory <IP Address or Hostname>(rw)
Not sure about the other file you mentioned as I don't necessarily run Redhat no longer. But if you have all the daemons and put the correct information in your exports file, then restart, the server should be ok.
Have you already gone thru the network setup during the Redhat installation? If so, on your NFS server, are you putting the hostname of the remote machine or IP?