Congrats Tanya! you'll love teaching...except for the first class I ever taught which I think scared me half to death and after it was over, I was home free! I am a Johnny G Level 2 instructor and putting together the music is one of the most fun parts of prepping. I too, spend a little too much time on iTunes.

Some other sources are:
www.pedal-on.com (lots of threads, search for them, on spinning profiles (very detailed with music and movement) and music)

www.spinning.com (there is an area for profiles, I don't think it's restricted via logon, so worth trying - also check out their pre-fab CDs and pick up some song ideas...then check out the song clips on iTunes or similar)

You'll soon find what you and your class enjoys...best of luck on creating your new profiles!