You'll probably find these three sites have all the links you'll ever need

Operastuff

Opera Glass

Operastars

Bruce Schoonmaker - baritone

My friend Bruce Shoonmaker always there to offer advice and support. Check out his site for valuable essays on all aspects of singing

Karen Mercedes - mezzo

Karen Mercedes mezzo soprano for quality pages on tenor Neil Shicoff, Georges Thill and many others

Vocal Pedagory - Forum for Vocal Students

Vocal Pedagory - Forum for Vocal Students