File Server

If you are going the Linux route, I recommend using Ubuntu for the distro. Compared to many other distros, its the easiest to use and setup. It never hurts to learn it.

The other option is to setup a Windows machine, use that for file serving. While having a vmware setup of Linux to play and experiment with. Once you figure it all out, you can move your files to it later.

When you start looking into raid systems, the learning curve starts to increase a lot. Software raid is generally the easiest. However, totally avoid the "soft" raid cards such as those produced by promise. I personally prefer 3ware, although they are way more expensive ... they have some unbelievable support via phone.

 

It really depends on what you want to do with the server...if all you want is a central place to store and share files, all you really need is a NAS (network attached storage). You can find some good suggestions in another thread. There are a variety of approaches you can take, ranging from an old, repurposed PC running a free Linux distro such as NASlite, to fairly expensive dedicated devices with built-in backup capability, etc.

RAID (redundant array of inexpensive disks) is a method of reducing your vulnerability to hard disk failure by replicating data across several physical disks (hence "redundant"). There are different ways to implement this, ranging from simply mirroring the contents of one drive onto another (RAID 1) to more sophisticated schemes (RAID 5, RAID 10, etc.). A RAID "card" is simply a hardware controller for a RAID array; Windows and OS X can also manage arrays from the OS itself (software RAID), but offloading RAID management tasks to a dedicated controller generally gives better performance. You don't need RAID on a server...it increases reliability and uptime, but is NOT a replacement for backing up.