Where to download samples?

I'm interested in getting a bunch of anime soundtracks, but I'm only
interested in certain songs.  I don't mind buying the entire CD but
I'd like to make sure that the song I want is on it first because it
seems like there's a million CDs for every series.  I'm mostly
interested in instrumental stuff.  Is there a website where I could
listen to short samples from CDs so I'll know what to buy?  Or if not
samples, a description of the music?  I'm not looking for free mp3s
here or to pirate anything but I'm poor and can't afford to buy ALL
the CDs for each series to find what I like.
Thanks!
~ravfladermus