I think tying the book in with the music is a great idea..maybe the author would let you put songs on his website.
Soundcloud will let you make a group of songs that you can then link to. The advantage there is that a listener who really likes the music has immediate access to all tracks. If you choose not to allow downloads from SC, you can link to a site like CD baby and maybe make a few sells off of it. I'm waiting for SC to eventually offer a paid service where it will cost people to download certain music...and then you make money too.
Posting a movie on YouTube is also helpful, with a link to a site they can buy from..........If you're looking for maximum listens to your track you almost need to be out there like a mad man for the first several weeks after release on all the social networks promoting it..and as soon as you stop doing that the track will probably be buried unless you can somehow keep the momentum going.
When I post one of my tracks on Facebook, I might as well pee in the wind...no one even notices it. A site devoted to your music on Facebook might help but I think many users stay away from anything that looks commercial on FB...most of them are there to catch up on news from friends.
Having
followers on soundcloud is your largest advantage .. the more people who follow you there will repeat play or play new tracks you make.Having sincere dedicated followers is probably one of the toughest things to get.
NOTE- Hey James I just interviewed another Scot by the name of John Moxey on my show...he touched on some of the ways to get music noticed.