For finding new music I enjoy, the main source would be various artists compilations. CMJ magazine has a great diverse selection of tunes on their monthly cd. Uncut, Mojo,
Pop Culture Press, Paste and other music journals often feature similiar various artist comps.
Through trial and error, I've learned which critics and which web sites give a good (and bad) judgement of a cd according to my taste. If sites offer sound clips, all the more better. Most new artists have sites that either provide sound clips
or links to sites with downloadable music.
I do use the listening station when cd stores offer them. They seem to have been phased out around here, except at Borders.
I wish i could list the radio as a great source of new music but
that's a parallel universe I've yet to travel in.