Stereogum

Stereogum is one of the best online resources for alternative and indie rock music. In addition to providing lots of reviews of rock music, they also provide lots of free mp3 downloads. Lots and lots. It's a great source for listening to new music. If you don't know what artists or songs to download individually, you can download an entire month's worth of free songs at once and just feed them into your mp3 player for hours of free rock.