On RedHat Enterprise/CentOS...
assuming your home server is called "fs1" and is sharing out /home over NFS. You'll also want to make sure that both your home directory server and the server you're running autofs on has the same passwd/user info - ids, gids.
1. Make sure autofs is installed and running:
sudo chkconfig autofs on
sudo service autofs start
2. add "/home /etc/auto.home" to /etc/auto.master
3. create the file /etc/auto.home and add these lines:
* -fstype=nfs,rw,nosuid,soft fs1:/home/&
4. if you already have a /home dir, move it out of the way:
sudo mv /home /home.old
5. reload autofs
sudo service autofs reload
6. ls /home
You should see the users' home directories.