Reddit mentions of The Inner Voice: The Making of a Singer

My two favorites are "The Complete Handbook of Voice Training" by Richard Alderson and "Singing Voice Rehabilitation: A Guide for Voice Teacher and Speech-Language Pathologist" By Karen Wicklund.

I like the first as it not only covers the basics of singing, it covers them from a teaching angle, as though you were trying to train someone else. It's very specific, and even though there's material that others will argue (as is common in books about singing) its overall quality is quite high. The second was very good for me to learn about the technical aspects of singing in near complete scientific terms. What exercises will help with some specific problems and exactly why, not to mention a great anatomy lesson.

And also, although it's not a book about vocal technique, I've found "The Inner Voice: The Making of a Singer" by Renée Fleming a useful insight to what the current vocal/operatic market is, and some generally good advice and food for thought for a young singer. It's basically her autobiography and advice to young singers, so it may help that I'm in the targeted audience for her book, but I love it.

It's interesting to see that operatic singing has been relegated to the realm of freaks with enormous voices and folks "just born with it." There are a multitude of roles in the repertoire for lighter or "smaller" voices, and they must cultivate the skill of singing into a large theater and over an orchestra just as well as the Brünnhildes. Renowned dramatic-mezzo soprano Dolora Zajick calls this subjective awareness kinesthetic empathy, and frequently likens the skill of learning how to identify when a voice isn't functioning properly to a famous choreographer who went blind but could tell how dancers were moving by placing his ear to the ground and listening to how they were landing. Genetics may exclude you from singing your dream role, but that's about as far as the "talent" element goes.

The most beautiful sounding voices are usually the most skillfully used, and while some have an innate sense of "how one sings" it can and has been learned by many-a great singer. There is absolutely nothing natural about singing the scales of absurd range and rapidity which are common place in opera, and while everyone is born with voices of unique timbres and sizes, I assure you that barring major physical ailments (deformities to the cords etc) everyone can learn to use them skillfully and deliberately.