What you say you want sounds a lot like what I set up where I live (albeit I rent a room, and the whole thing is jury rigged)
From what I can tell, most of what you need is to simply set up a file share. In this case you would need a PC at each location, and for movies, you would need them on an HD (either shared or local). If you want TV stuff over this, then it becomes much more complicated. BTW, why no internet? If you have the ethernet strung and the computers, might as well use it for internet as well.
The whole home fileserver system I have set up cost almost nothing. Two recycled computers ($0) (one for the file server and one for the livingroom entertainment center), 2 1 TB external HDs (hooked to the file server for content) ($120 each), some ethernet (say 40 bucks). A remote for the livingroom PC (40 bucks). Plus already had a router. This allows all 6 computers in the house to access all content on the fileserver.
Maybe it would be helpful if you expressed what you really want out of the system vs cost in more detail. Otherwise it can be hard to help.
EDIT: It may have seemed like I was parroting the above poster, but there are some major differences in basic setup. Well.. Not really, but the devil is in the details. EG NAS = Network Attached Storage Fileserver = dedicated computer setup on the network to allow other computers to access its storage. The basic concept is that NAS = Fileserver, but even more basic is that NAS does not equal fileserver... Understand?
EDIT2: This might be something useful you can play with until you get better answers: If you have a router and atleast 2 computers, set them up under one network neighborhood and make one of the drives on one of the computers sharable (Right click on the C: drive and go to share. From there click on the option to allow it to be shared). Play around with this stuff for a bit to get used to the idea of shared drives/folders and how they work. EDIT3: To see the shared drive from the other computer, you will have to (at least at first) go to: (Vista, start menu, network) (XP, right click on the task bar and go to properties, in advanced there is an option to add "network neighborhood" to the start menu. After doing that, click start and go to network neighborhood. From there, click on all network(or microsoft network) then click on your workgroup (default name is workgroup), then click on the computer you want to access the drive from.) Phew... From here you can make a local shortcut on the desktop to the shared drive. You can also mount a network drive in the "my computer" window. (Guess it isnt as easy as I thought, atleast not to communicate the steps....)
Sorry: EDIT4: Linux: If you have a linux box on the network and want to have it see your PC's shared drives/printers you can:
1. open a root terminal and type /etc/init.d/samba start
2. Find the Samba Server program for your version of linux and click on it
beyond that, it gets a bit more complicated...