there are many, many information sources that I use for research, and I pay close attention to music I hear in Movies, TV, Radio, etc. Here's my list somewhat in order of best to worst:
1) Amazon.com - I use their recommendations, surf genres, read reviews . . . these lead me to new artists and music. This research process is also applied to the next 3 internet sources too. The resarch leads to listening to the sound bites. If I like, I buy. If I like it when it's delivered and I've had the chance to listen to the whole thing, I use it to begin the next search.
2) Audiogon discussions. . . followed up by surfing Amazon.com
3) Other Music web sites - Artist sites, Progressive Ears, Allmusic.com, etc. I start with somone I know, follow the reviews and artist history to other music and artists
4) Joe's Record Paradise - my new source for used vinyl. I search the racks and buy.
5) Music I hear in Movies, and on TV
6) Recommendations of friends, relatives, acquintences (my teats are pretty eclectic, maybe strange so this isn't as productive as one might think it would be.
7) Radio - Stations around me are bad, and I really don't like much of what I hear on FM, but now and then something comes along.