The American Theatre Wing is a great resource on information about working in each specific discipline of theatre. I gathered together some interviews that addressed different aspects of music directing:
SDCF Masters of the Stage
Working with Dance Arrangers - 2010
Broadway choreographers and dance arrangers discuss the role of the dance arranger.
The Musical Director - 2001
Ted Chapin interviews Paul Gemignani, who has received a Tony Award for Lifetime Achievement for his career as musical director for over 35 Broadway musicals.
In The Wings
Interview with Music Director Carmel Dean - 2010
Carmel Dean has worked closely with William Finn and Tom Kitt.
Interview with Orchestrator Christopher Jahnke - 2010
Christopher studied with William Brohn, orchestrator for Miss Saigon and Wicked, and worked closely with David Bryan on Memphis.
Interview with Sound Designer Robert Kaplowitz - 2010
Robert is a Tony Award winning sound designer
Interview with Voice Teacher Linda Benanti - 2010
Interview with John McDaniel - 2004
John was the Music Director for Brooklyn The Musical
Its fascinating stuff, check it out!!