Betwixt and Between - Tales of the Mid-World, #1

When young Jerry dies as the result of a car accident, he finds himself in the Mid-world, a place between the First-World of the living and an unknown Third-World that can only be reached with the aid of a Transitioner. But finding a Transitioner proves more than a little difficult. The Mid-world is a strange place populated with elves, gnomes, trolls, dwarves and other creatures known to the living only through stories.
Nevertheless they are real and some are very dangerous. It is a world in which a particularly dangerous magic user is attempting to increase his power and before Jerry understands his own situation, he is caught up in in a web of intrigue and danger as the elves, and eventually the dwarves, attempt to save their own world; and, by extension, the world of the living.