I have never messed with RAID, but I plan to make my system a RAID 1 box, soon.
So I am afraid, I can't really help you. Just one thing I read: Some hardware RAID controllers
- won't run properly with Linux, and unfortunately there are some Promise models among them; I suggest you check the Linux hardware databases, like
http://cdb.suse.com. If your controller turns out not to be well supported, remove it from your system which can be a problem if it is an onboard controller, or configure it as a usual IDE controller.
- just pretend. Actually they just do everything in software (firmware), and nothing more than the Linux kernel could do itself. Try to find out, if your controller is one of them, and if so, set up your system as software RAID. A first hint might be the price tag: real hardware controllers offer more speed and additional data protection, but they tend to cost three or five times of what a low-end pretender costs. I don't know the US prices, but in Europe a hardware controller is about 250 Euros, at least. Products from reknowned makes are about 300-600 Euros. Everything below is not doing anyhting the Linux kernel couldn't handle for you.
For your other questions I recommend the RAID howtos on
http://www.tldp.org. And LQ and Google and Vivisimo are your friends, of course.
gargamel