This book will give you an understanding of acoustic instruments and voices that will dramatically improve your knowledge of sound production and arranging.
Don't be put off by 90s hardware on the cover. This is as relevant for music writing (after digesting some chord theory etc) whether you're on said hardware or Reason 6 or other software. I bought a legitimate s/h copy with no CD included: if any one would provide the sound files, I'd be most grateful; 128kbps AAC/MP4, WAV, AIFF or AL files please!