I suppose most people beginning with Zelazny's stories will start with the Amber chronicles, definitely these days with no new releases due to his untimely (and highly lamented) death. The Amber stories are fun to read, easy yet quite light, enjoyable yet never really thought provoking.
Not so for this book, it requires a full focus from the reader at about all times yet the rewards are much higher too. It's never easy prose and similar to "Lord of Light" and "Creatures of light and darkness" (and several other stories), it taps into a religious/mythological/spiritual background, this time Navajo. (apparently, Zelazny was heavily inspired by Tony Hillerman's stories for this)
It's hard to say more about the book without spoiling it, I'ld say it's basically about a man trying to find peace within.
More than worth a read!