External array

Hi

I've been reading about RAID, and I'm a bit lost. I've heard its a good solution, and that it enables me to show all hdds as one. I have also heard that it is not the greatest solution, especially on Windows.

What I want to do, is hook up my 3 external hdds, to my laptop, to hold all my music and movies.

What I don't know is what the best solution to that is.
Do I use RAID?
Do I simply plug them all in via USB and have the 3 separate drives shown?
And what do I do about backup?
Should I back up, or should I not bother with so much media..

Thanks much.