IWTL about music

One of my roommates and several of my close friends are very into music but I know almost nothing about it. I don't mean technically, because I actually do know a thing or two there, having taken piano lessons for a few years (I was pretty good but stopped during high school when I didn't have the time). Basically what I want to do is cultivate some kind of taste in music - expose myself (eyy) to new artists/genres/styles, learn about important musical movements, the major artists everyone should be familiar with, etc.

I am pretty busy as a full-time student who works 20 hours a week, I also watch movies quite a bit, since film is my main passion, but I think I should be able to find time to listen to an album every now and then. How do I go about this?

my pathetic list of favorite artists at the moment:

• David Bowie

• Leonard Cohen

• The White Stripes

• Bob Dylan

• The Replacements

• Explosions in the Sky

also, I'm interested in electronic/techno but haven't heard much, I also like some opera (my dad made me listen to Wagner as a kid, and I revisited Parsifal recently and really liked it), classic hits ("oldies"?), and I heard a Fugazi album that I really liked...what's that about?