This is based on CentOS but should be very similar for other distros as well.

If NFS is not installed install it

yum install nfs-utils

Have NFS start at startup

chkconfig nfs on

Create a directory to share

mkdir /nfs

Change the rights on the directory to allow users to create and delete data

chmod 777 /nfs

Edit /etc/exports to share the NFS directory

vim /etc/exports

add the following to allow the subnet 192.168.0.0 read/write access to /nfs

/nfs        192.168.0.0/24(rw)

Restart nfs service

service nfs restart