The online site for NATS (National Association of Teachers of Singing) has all kinds of useful info about upcoming events, contests, publications, and SNATS (Talk to Dr. Weiler about SNATS!).
Classical Singer is a must for those of you who are interested in a classical career. This is a subscriber site that is THE bible of auditions for the opera industry. It has lists of competition, summer program, opera company, crossover, and even temple/church position auditions. The site is also searchable by the experience required, the size of the company, and more.
Looking for an aria to sing, or wondering whether an aria is in your range? Search no further than Aria Database. The database has a diverse collection of information on over 1000 operatic arias. The Database includes translations, and many aria texts, as well as a collection of MIDI files of operatic arias and ensembles.
Theory and Ear Training
Music Fundamentals is a site which will prove helpful to those struggling with basic theory. I cannot recommend this site highly enough. It has everything to help someone trying to learn theory, including rhythmic dictation, interval exercises, clear explanations of Augmented Sixths, Neopolitan chords, and secondary dominants…and so much more! Even if you’re good at theory, it’s a fun site to check out!