3 tips I have.

to find a song you're not sure what it is put some words you know in quotes in google and the word lyrics

evilyrics http://www.evillabs.sk/evillyrics/
shows the lyrics for pretty much any song you might be playing in winamp, media player, itunes

to find mp3s in google use the search expression e.g.
"rammstein" intitle:index.of mp3 -html -htm "last modified" "description"