Natya Shastra - The Natya Shastra is the oldest surviving text on stagecraft in the world. This work lays down the fundamental Hindu concepts of art in general and music and dance in specific. - http://www.chandrakantha.com/articles/indian_music/natyashastra.html
Broadway Press - Publisher of many technical theatre books. - http://www.broadwaypress.com/
Stage Managing Book - A book for novice or experienced Stage Managers. - http://www.stagemanaging.com/