Help Setting Up Home Media Server

Hey everyone,

I was hoping that I could come to this board and get some help with setting up a home media server. I am fairly experienced with computers and networks, but I can't seem to figure out to accomplish my goals. Currently, the way I am set up is that my computer stores the media (TV Shows, Movies, Music, etc) and shares these over the network to the other (4) PCs in the house. However, when my computer is sleeping or off, they cannot access these folders for obvious reasons. To this end, I'd like to set up an extra computer that I have in the house to act as the media server.

I have a wireless router which is currently full up (4 ports). I also have an 8-port switch that is not currently being used. All the machines are running 7 except for one which runs Vista. I'd like to configure the home network so that all the computers that are wired in can access the same network (EX: I also have Vonage in the house, and the one computer that is connected through the extra port on the vonage box can not see the other computers) and I'd like to have full Read/write control from my machine, while not allowing anyone else on the network to add, modify, or delete the files. My family is not the most computer literate, and I do not want them being able to accidentally re-name or delete the media files that I have organized and stored on this machine.

Is there an easy way to accomplish this? I was thinking that if I set up the switch (not really sure how these work, if I plug it into the router and then plug computers into this, will they see each other?) I'd be able to create two accounts, however it seems that if I share it, I have to give everyone read/write or nobody. I don't want to have to go to the machine each time I need to add or change something.

If anyone can point me in the right direction, or even provide me a how-to, I would be eternally grateful.

Thanks,