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.
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.