Peter Alexander's Professional Orchestration series. Vol 1 is the instrumentation manual, Vol 2a/b is for the melody in strings, melody in winds, and melody in brass. Vol 3 is coming out around this time next year, and is melody in combined sections. Vol 4 shortly after will cover harmony of the sections. debussy's la mer, particularly the first movement and the dialogue of wind and sea are remarkable, particularly the string color/and divisis. ravel's mother goose suite is simply amazing in all aspects. I have the complete handwritten scores to countless John Williams works, all of Indiana Jones, all of Jurassic Park, Most of star wars, all of ET, and more. that's probably the greatest single resource on orchestration, john william's handwritten scores. thomas goss is getting ready to come out with his own orch course, join the orchestration online group on facebook or lookup orchestration online on youtube. robin hoffman has fantastic daily scoring bits. the overtures of wagner operas are pretty clever, look for the flying dutchman and parsifal in particular. dutchman has awesome string writing, check how he doubles what strings with which wind/brass and at what intervals, and when they change. analyzing flying dutchman like this will really get you memorizing the sound of different intervals and different doubles. it's mostly your own personal score study.