Re: NAS or not
well there are obviously two ways to back up, one called push method, one called pull method.
the push method is where the client is in charge of sending the files to the central server store, Using this method you'll have to stagger the opperations because of the amount of traffic...
the second mothod is pull, use a server, (which we'll call your back up server) to retrieve the files you want to backup from the client computers. the best part about this method is you don't worry about staggering the opperation, the way I see it, you have two distinct options...
1, use backup software, this is obviously the best option from a corperate point of view, but if you are literally just copying files from computers to one large network server, there is very little benefit in paying for profesional software...
which brings us to option 2.
batch files... I suggest that you write a batch file to copy the data from the computers to the central storage location, the only negative here is that it's a little harder to get a log of the opperations (though not impossible).
either of these two methods will only copy one file at a time, so your staggering is (virtually) done for you, and there is no need to bother about setting up the staggering.