Tales of the South Pacific by James A. Michener — Michener spent part of World War II based on Espiritu Santo and used his experiences in the New Hebrides as the backdrop for this Pulitzer Prize-winning collection of linked stories. The islands are thinly disguised but recognisable. Essential reading before any trip.
Return to Paradise by James A. Michener — A follow-up collection of essays and fiction in which Michener revisited the Pacific islands a few years after the war. The Vanuatu chapter captures the New Hebrides before tourists arrived.
Kava: Medicine Hunting in Paradise by Chris Kilham — A readable account of kava's cultural role across the Pacific, with substantial attention to Vanuatu, where kava culture is deepest.
Arts of Vanuatu edited by Joel Bonnemaison and Darrell Tryon — An academic but accessible survey of traditional art, material culture, and kastom across the archipelago. Good for understanding what you are looking at in village contexts.
Tanna (film, 2015, directed by Bentley Dean and Martin Butler) — Not a book, but worth noting: this Oscar-nominated film was shot on Tanna with a cast of real kastom villagers telling a story about love and tradition. Watch it before visiting the island's interior.