Your title is longer then your post... :/ Anyway, I get music from many different sources. Itunes is ussually my last resort, and for the most part, I use Pandora to find music and LimeWire to get it. Sometimes I get music off of the Newgrounds audio portal though, and sometimes I stream it into iTunes through a link. ... I guess I get music from just about everywhere.
You just have to be careful what you download, make sure it's not one of those files that pretends to be what you're looking for but isactually just what you typed into the search field, but maybe in caps, or something like that. It gets really irritating. I don't really worry about viruses though, I have the POWER OF APPLE
I usually always just go to the store and look for bands that I already know, or who I've heard of. But if I'm to listen to music online it would be imeem or youTube. I never download, or purchase, so, yeah.