The current (October) issue of Recording Magazine includes interviews
with two engineers who worked at Motown in its early years: my interview
with John Windt and George Petersen's interview with Mike McLean.
Talking to Windt was fascinating, and Petersen's article (which begins
with his discovery of one of Motown's mastering equalizers at a flea
market) dovetails with it nicely. The focus of both interviews is on
equipment and production techniques.
Recording is sold at large bookstore chains such as Barnes and Noble,
and at some branches of big-box music stores like Guitar Center.