compaq proliant ml370 server

I was just given one of these to use for myself. The hard drives have all been taken out of it and disposed of. I am new to this computer stuff but know enough to be dangerious. LOL! I need to find out where I can get info on as to what kind of hard drives they were and where I might be able to get some to replace them. It looks there were three of them in it. Do I need that many? Any help on this I will be really greatful for.
Thanks a bunch!
Keith