Laura Claycomb's Young Artist Corner: This is a fantastic and comprehensive site with excellent advice for all stages of a young singer's career, including education, competitions, recommended reading, self-promotion, and much, much more, all based on the experience of a talented singer who's been there. Highly recommended.
The New Forum for Classical Singers: A wonderful message board for professionals and young artists to trade advice, share experiences and lend support.
Operabase: What's playing and who's singing at every major opera house in the world.
The Opera Critic: Opera reviews and articles from around the world. (Requires subscription)
Musical America: Publisher of the best directory for classical music in the world, as well as a website with many resources for professionals. (Requires subscription)
Classical Singer Magazine: Articles, resources, and forums for singers getting started in their careers.
Classical Voice: News and reviews.
Opera Today: Articles and reviews.
Viva La Voce: FREE streaming opera and classical song!
The Lied and Art Song Texts Page: Search a database of song texts and translations.
Classical Music Search: Ever had a classical piece stuck in your head and just couldn't remember where it was from? Play it into the keyboard in this applet and it will deliver composers, pieces, movements, catalog numbers, and MIDI examples from a database of over 1500 classical melodies.
Peter Schickele's home page: Composer, musician, musicologist, host of Schickele Mix, comedian, creator of Baroque ne'er-do-well composer P.D.Q. Bach, and my personal hero.
Parterre Box's La Cieca: Opera gossip.