Short answer: google 
Long answer: try this one:
http://www.ubuntugeek.com/nfs-server-and-client-configuration-in-ubuntu.html
One warning though: if you are not familiar with the "vi"-editor perhaps replace the vi in the commandlines with gedit or kedit. You can also use the following two commands:
sudo su
mkdir /nfs && echo '/nfs *(rw,no_root_squash,async,no_subtree_check)' >> /etc/exports && exportfs -r
This creates the dir /nfs and exports it for all hosts - if you want to export it for only specific hosts use something like:
echo '/nfs 10.1.1.10/255.255.255.255(rw,no_root_squash,async,no_subtree_check)' >> /etc/exports
echo '/nfs 10.1.1.0/255.255.255.0(rw,no_root_squash,async,no_subtree_check)' >> /etc/exports
fejf
--
There are 10 types of people. Those who understand binary and the rest. And those who understand gray-code.