Books on audio measurement / sound system design and engineering:
Meyer Sound Design Reference – Bob McCarthy
Sound System Design & Optimization – Bob McCarthy
This Google Link allows you read some of Sound Systems: Design & Optimization

Articles & PDFs

JBL Pro – Sound System Design Reference Manual PDF
Spectra Foo – multizone measurement
Spectra Foo manual – distilled to just transfer function information
Bob McCarthy blog
The Emperors New Stereo
Phase Alignment of Subs
The ABCs of Line Array Tuning
Toning Your Sound System

WIKI – Fast Fourier Transform
WIKI – Loudspeaker Measurement
WIKI – Measurement Microphone Calibration
ARTICLES ON AUDIO MEASUREMENTS
synaudcon.com – test and measurement article page
Whats the measurement? Understanding and properly using RTA & FFT
FFT Fundamentals