This seems like a good thread for my first post. :)
I'm a big Todd Rundgren fan and when I found out he also did production work I started looking for artists he had produced. The internet and Wikipedia have been a welcome help for me in discovering new music. Sometimes I will look up a band or solo artist and then see who else they may have performed with.
I will also check out what friends listen to from time to time, but most of my friends are quite a bit younger than I, so our musical tastes are quite different.