Basic RAID concerns and Linux OS

In our small business, we have to hold onto gigs of data. And sadly, disgustingly, we don't have any good backup (periodic DVD burning when we can) and the PC holding the info just has a couple of ATA HD's.

We're needing to put together a file server, and I'm looking into mobos that handle RAID 10. From what I can see, that's the best balance of efficiency and performance even with the 50% size usage.

Here're my questions: I am finding it hard to find info on how the RAID is managed and if a drive fails, how to replace it and rebuild the array. Some info I REALLY need to know before I set one up. =) I've found lots of info about what an array does but no real meat on managing an array. Any pointers of where I can go to find actual how-to's would be appreciated.

I'm pretty comfortable with Fedora Core. But, I'm also looking into Slackware since a lot I've found indicates it's a bit (or a lot) more stable, secure, and tested. So, does the OS handle array management, or software apart from the OS? (When I installed a SATA on my own PC I had to install some HD software that loads up before the OS does. So does picking the OS matter too much when considering RAID?

And, how hard is it to replace a RAIDed drive? If I have a RAID 10 and a drive goes bad, is it as easy as replacing the drive and selecting something in a program that "rebuilds the array"? (How would I know a drive's gone bad anyway? Does the RAID do a constant parity check and whatnot and let me know of abnormalities? Or do I have to run an FSCK or something now and then?

Thanks for any feedback and information! -Liam