Questions (RAID, SCSI, etc) - ANY help appreciated!

Well, as high school winds down, meaning I still have work to finish, my
summer-job boss is attempting to buy a server. My exposure to the server
environment is mostly theoretical -- that is, I lack real-world experience.
I will confess right now that my place-of-work is all Windows-based. This is
largely due to the fact that we use a lot of proprietary Windows-based
software, and they are interested in integrating UN*X onto the network in
the future. I hope you guys can overlook the Windows thing, especially since
most of the questions are hardware-based. ;)

Anyway, I need to stop rambling (blame it on lack of sleep) and get down to
the questions I have, which I hope some of you will be kind enough to help
me with. I know this is very off-topic, but I am in a real time-crunch, and
this listserv has some of the most well-informed techies I know.

1. How exactly does RAID 0+1 work? Let's say I have two 18Gb drives in a
RAID 0+1 configuration; does that mean I'll basically have one 36Gb drive
(RAID 0) *and* still have mirroring (RAID 1)?

2. Let's say I have a SCSI controller (Embedded Adaptec AIC-7899 dual
channel Ultra3 (Ultra160)/LVD SCSI). If I have two SCSI drives, of the same
size, what else do I need for hardware RAID? One RAID controller, or
something else?

3. In a RAID 5 configuration, let's say I have 3 18Gb drives -- they will
show up as one 18Gb drive, right? (I *think* I understand the
mirroring/parity bit concept.) What if I add another drive (a 4th drive),
will it still go into the same array which will show up as one 18Gb drive? I
thought I had the answer to this, but I couldn't convince my employeer.

4. What's the deal with software RAID? Is there a significant performance
hit? And, if you don't mind answering...are there any "free" (free beer)
software RAID solutions for Windows 2000? I admit I haven't had a chance to
Google about this question, yet, but if anyone wants to offer any insight,
that'd be fantastic.

5. Some SCSI drives are advertised as 68pin, others as 80pin. Does each
particular SCSI controller have a particular pinout, or what? Should I just
research the controller mentioned above to figure out what sort of pinout I
need?

Anyway, sorry for being such a complete cluebie -- hopefully this can be a
learning experience for me. I am trying to get 200 things done at once,
including graduate high school, so any answers you can provide would be
helpful.

Thanks in advance!

---
Vitaly McLain <[email protected]>
"Don't worry about people stealing your ideas. If your ideas are any good,
you'll have to ram them down people's throats."
     -- Howard Aiken