Hello, glad you got nfs working. The file /etc/exports sets up the nfs exports. There are many possible configurations, I'll show you what I use:
The first part is the directory you want to share, the numbers say to share the directory with everyone on my LAN. Make sure there is no space between the end of the numbers and (
rw - enable read write access
sync - Do synchronized coping. I have played with the options and this is what I recommend.
all_squash,anonuid=33 - force everyone using the drive over nfs to be the user www-data (userid 33) This is the samba user that you would be using on your vista box. Of course, if you have a different setup you can see the user id of all users in the file /etc/passwd.
Now, on your client *nix machine you can type (as root)
mount 192.168.1.2:/shares/internal/PUBLIC /home/you/MyBook -o rw
Make sure the directory where you want to mount the drive exists. Oh, my MyBookWorld has an IP of 192.168.1.2 (on the internal LAN - not the internet) so change this to be the IP of your MyBookWorld.
To make this happen when you login, edit /etc/fstab on your client and add:
192.168.1.2:/shares/internal/PUBLIC /home/you/MyBook nfs rsize=1024,wsize=1024,noauto 0 0
For a media server, I recommend that follow the tutorials for setting it up as a media server. I haven't done this so I can't say which is best.