apt-get install portmap nfs-common nfs-kernel-server
edit /etc/exports with something like (for lets say a public share):
/srv 10.0.0.0/24(ro,no_root_squash,no_subtree_check,insecure)
After saving, import the shares using:
exportfs -a
OR
/etc/init.d/nfs-kernel-server restart
DONE!