There once was a novelization of the movie,
It's out of print 'cause no one thought it was groovy,
Take out all the songs and add some trippy scenes,
Then make the Fierys dark and boring.
At least that's my interpretation of it. It pays a little more detail to some of the implications in the movie (like how we only know her mother left for a star from her scrapbook, but the book mentions it outright), completely rewrites whole sections of it, draws out the Fiery scene for far too long (I felt like tearing off heads by the end of the scene).
But there are people who like it, IIRC. It's just not for me. I kept reading thinking I could have done better.
Search the internet for the Labyrinth novelization. A text file is floating out there somewhere. I know it's been linked to a few times on imdb.com's forums for the Labyrinth.