I actually don't think there are any published books with a huge list of contacts, as it would cover too many genres, departments, etc. plus employees change so fast in the music industry that the book would constantly be updating and out of date.
I Google things like that, and every once in a while you'll come across a name and address/email. I always send an introduction email, and rarely get them back. It'll be a lot of searching, hoping, emailing, and waiting, but eventually you'll strike something.