Right. MC doesn't particularly care where the media files themselves are stored. That's the beauty of the database! I have a Server copy of MC that runs at the office that doesn't have ANY local files (it is in a VM, in fact, with very little local storage outside of room for Windows and MC). All of the content in its database lives on various SAN locations on our corporate network. I have a bunch of different shares added to Auto-Import via their UNC paths (I don't know exactly how many right now, IT keeps rearranging my shares because they're big, I think).
One tip, though, if you go this route... Add all the files to MC via their UNC paths (\\servername\share\path\to\media.flac) rather than via their local pathname (D:\media\music\path\to\media.flac) and it'll work better. The reason is that you won't have to muck about with drive letters and mounted network shares to make sure all the pathnames match on the client and server. Plus, if all the machines are on the same LAN, then all of those files will be treated as Local playback (and won't have to be streamed), assuming that each box has permissions to connect to the share (they all use the same username/password, or you ensure that all users have read/write access to the files and shares in question). The terminology can be a little confusing, but by "local" in the context of this option, it means "can the client get to the actual file via the same exact path that the server uses to access it?" Network drives and UNC paths, if they're accessible (and named identically), count as local in this context.
The option to play local media if one matching is found is enabled by default, so you don't need to worry about that. You will want to enable authentication (to allow tagging changes to propagate back to the server from clients), though.
So, if you add the media to your Server via UNC paths (even to "itself" for content that actually lives on the server box), you'll have good results on the clients (which will be able to access the files via the same exact "path").
So you're aware, though, even without "locally matching files", the Server will stream the files that the client can't find "locally". This is handy for playing files from your server on a laptop when you're "on the road" or whatever. It works way better with music than it does with video, currently. However, this will cause all of the "streamed" content to be transcoded before playback, which causes some latency, and impacts seek performance (you have to wait for enough of the file to be streamed in before you can seek substantially in the file, in many cases). To have this feature work outside of your home Firewall, you will need to open the port to the Media Center server. Also, even inside your LAN, you might need to open the port on the Windows Firewall if you have that enabled (or any other software firewall).
All of this stuff is configured via: Options > Media Network. The important stuff is:
Options > Media Network > Authentication: Enabled
Options > Media Network > Client Options > Auto sync with server: Enabled (turn on for each client, though I believe it defaults on, but check it)
Options > Media Network > Client Options > Play local file if one that matches: Enabled (is by default)
The stuff under Client Options is client-specific, so it doesn't matter what they're set to on the Server copy of MC.
Then, on the server box, enable Auto-Import, and add all those same UNC paths to the Auto-Import watched folders list. It can handle UNC paths just like it handles any other drive letter. If the box that serves the file is down or missing, Auto-Import will just ignore it until it comes back to life (though those files will be unplayable during the downtime). However, make sure that you don't change the default Fix Broken Links setting in Auto-Import to anything other than No or Yes (Protect files on missing drives) (the default), or it'll remove the "missing" files when/if the host goes down.