Warning: This list is entirely subjective, and only includes artists whose releases I personally collect and enjoy. I skipped linking a few dozen of my most marginal acts, as well as classical names. This is primarily a personal reference tool, but others are welcome to borrow its usefulness.
I have selected the best links I can find, after careful research. Off and on, it took over five years to fill in a link for every name (page first "finished": March, 2003.) The page is also regularly monitored with link-validation software -- the success rate of these links is much higher than on any other such site I've seen. Still, there are always a few broken ones. Email me to point out a dead link, or a link which might be upgraded to a better location.
Recently added links: Arctic Monkeys, Lou Barlow, the Beards, Caribou, Deerhoof, Matt Elliott, Hal, Peter Holsapple, Imitation Electric Piano, Gary Kail, Maxïmo Park
Recently updated (as of 4/23/08): Aloha, Virginia Astley, Badfinger, Belle & Sebastian, Simon Bonney, Tim Buckley, Vic Chesnutt, Elvis Costello, the Cramps, Downy Mildew, Enon, 50 Foot Wave, Juliana Hatfield, Helmet, Jimi Hendrix, Hüsker Dü, the JPS Experience, Kitchens of Distinction, Daniel Lentz, Mull Historical Society, James Newton, Iggy Pop, the Rolling Stones, Rosa Mota, Shockabilly, Sing-Sing, Patti Smith, the Soft Boys, Stereolab, Brian Stevens, Swell, Toy Love, Tom Verlaine, the Webb Brothers
Need fixing: Let's Active, John Linnell, Living Colour, the Modern Lovers, Van Morrison, Neu!, Pizzicato Five, Yello, John Zorn