Came across this EXTREMELY comprehensive tutorial to orchestral composition on Youtube. This guy actually goes through every single step of composing a song down to mixing and mastering. Complete with sense of humour as well.
Be warned though, grab a cold drink and a nice fat bag of popcorn before sitting down; Its VERY long.
Composition Part 1: Melody
Composition Part 2: Harmony: http://www.youtube.com/watch?v=UDHDvZO8 ... re=related
Composition Part 3: Arranging: http://www.youtube.com/watch?v=2MTfoHsA ... re=related
Composition Part 4 : Orchestration (Strings): http://www.youtube.com/watch?v=2Bg_xxdb ... ure=relmfu
Composition Part 4B: Orchestration (Brass): http://www.youtube.com/watch?v=44o7I0ap ... re=related
Composition Part 4C: Orchestration (Woodwinds): http://www.youtube.com/watch?v=0LWtUPvR ... re=related
Composition Part 4D: Orchestration (Percussion): http://www.youtube.com/watch?v=rG9siila ... re=related
Composition Part 5: MIDI 1 (Strings): http://www.youtube.com/watch?v=zrOG3pw- ... re=related
Composition Part 5B: MIDI (Winds): http://www.youtube.com/watch?v=veSWI_4n ... re=related
Composition Part 5C: MIDI (Percussion): http://www.youtube.com/watch?v=XEd5DvGA ... re=related
Composition Part 6: Mixing and Mastering: http://www.youtube.com/watch?v=KVnwLMojoOg