Home server

I have a belkin modem , i also have three computers . I would like to set one of them up as a server . I have a network going on at this time . but i would like to know if it’s posible to set one up as a server using the belkin modem . Two of my computers are running win xp pro and the last xp media edition . is it possible ? and what do i need to know as i’m a vergin to this kind of thing .