Here is a list we've compiled of singer's books that will be of use to you. 
The links below are some of the best deals we've found on Amazon. 

SINGER'S MUSICAL THEATER ANTHOLOGIES

SOPRANO

Singer's Musical Theatre Anthology,Vol. 1: Soprano (Book/CD)

Singer's Musical Theatre Anthology, Vol. 2: Soprano (Book/CD)

Singer's Musical Theatre Anthology, Vol. 3: Soprano (Book/CD)

Singer's Musical Theatre Anthology, Vol. 5: Soprano (Book/CD)

MEZZO SOPRANO/BELTER

Singer's Musical Theatre Anthology, Vol. 1:Mezzo-Soprano/Belter (Book/CD)

Singer's Musical Theatre Anthology, Vol. 2: Mezzo-Soprano/Belter (Book/CD)

Singer's Musical Theatre Anthology, Vol. 3: Mezzo Soprano/Belter (Book/CD)

Singer's Musical Theatre Anthology, Vol. 4: Mezzo-Soprano/Belter (Book/CD)

Singer's Musical Theatre Anthology, Vol 5: Mezzo-Soprano/Belter (Book/CD)

TENOR

Singer's Musical Theatre Anthology, Vol. 1: Tenor (Book)

Singer's Musical Theatre Anthology, Vol.2: Tenor (Book/CD)

Singer's Musical Theatre Anthology, Vol. 3: Tenor (Book/CD)

Singer's Musical Theatre Anthology, vol. 4: Tenor (Book/CD)

Singer's Musical Theater Anthology, Vol.5: Tenor (Book/CD)

BARITONE/BASS

Singer's Musical Theatre Anthology, Vol. 1: Baritone/Bass (Book/CD)

Singer's Musical Theatre Anthology, Vol.2: Baritone/Bass (Book/CD)

Singer's Musical Theatre Anthology, Vol. 3: Baritone/Bass (Book)

Singer's Musical Theatre Anthology, Vol.4: Baritone/Bass (Book/CD)

Singer's Musical Theatre Anthology, Vol.5: Baritone/Bass (Book/CD)