Unless you don't have the bottomless pockets of dough to dump into a NAS... Which is a lot of people.
Why even run it on a network to begin with.. Unless I'm missing the point of NAS..
In any case one shouldn't look to RAID setups for redundancy or reliability, and I'll explain why.
When you create a dynamic volume in an array (RAID) whether hardware-side or software-side, your computer will recognize the drives the array contains as a -single- volume. This means that even in a Mirrored RAID (RAID-1) with identical data mirrored to two drives, if you have a corruption or partition/volume failure, or say a drive fails, the volume breaks and you have to then attempt recovery of the volume, regardless of which drive caused the issue.
If you were looking to stripe the array for a boost in speed and to consolidate your data, you could do that with a better justification than a RAID-0 array, but the same problems still exist, with the added risk of not recovering ANY of your data at all because it will be sprinkled across multiple drives in bits and pieces.
Another alternative is a Spanned Volume, which includes two or more drives in a volume, filling up one first and then the second and so on. But this only functions differently than mirrored by well, not mirroring, doesn't offer performance boosts, and comes with the same risks as RAID-1 does.
Personally, I run a RAID-0 across two 1TB drives for HD media storage, but they're Enterprise-Level Seagate Constellations that I had the good fortune to fall into, and aren't cheap.
So if you're going to trust your data on a RAID, then you should definitely do some research on HDD reliability beforehand.
"I am to raid as i have never used it in the past."
This is a BAD justification to try anything!
My recommendation is that you get some nice, fast, cheap storage, like any drive with Advanced Format 4K (which is pretty much everything nowadays), 7200RPM on speed, and SATA2 or better, high-end cache (32MB or better) and run it as a simple volume.
If you are really concerned with backing it up, actually back it up to a separate single volume! This will give you the greatest level of data security period.
Personally, I've been impressed with Seagate's new Barracuda 7200, the ST2000DM001 (2TB). I can hit 150M/s + transfer rates, and the 1TB platter density gives it great seek-time response for such a large drive. They've also come down in price and at 130 bucks on Newegg, on the rear-end of the Thailand flood, are effectively a steal IMHO.