Black, Dave: Essential Dictionary of Orchestration: Ranges, General Characteristics, Technical Considerations & Scoring Tips (Alfred, 1999)
Debussy, Claude: Three Great Orchestral Works in Full Score (Dover Orchestral Scores): Prélude a l'Après-Midi d'Un Faune, Nocturnes, La Mer (Dover, 2009)
More advanced reference can be had in either of the following publications:
Adler, Samuel: The Study of Orchestration (3rd or 4th edition, W.W. Norton, 2002/2016)
Piston, Walter: Orchestration (W.W. Norton, 1955)