The Count of Monte Cristo by Alexandre Dumas (1844) — Dumas set part of his most famous novel on the Château d'If off Marseille, but the world of the Riviera aristocracy he describes — lavish entertainments, spectacular wealth, the interplay of French and Italian cultures along the coast — is very much the world that Cannes was built in. Read it before the trip and the Côte d'Azur will feel like familiar territory.
Tender is the Night by F. Scott Fitzgerald (1934) — Fitzgerald's novel of American expatriates on the French Riviera in the 1920s is set mostly in a fictional version of the Riviera coast. The glamour, alcoholism, and inexorable decline of the protagonists captures something true about the seductive trap of this particular landscape.
The Day of the Jackal by Frederick Forsyth (1971) — Much of the action takes place along the Côte d'Azur as the Jackal moves toward his target. Forsyth's attention to the geography is precise, and reading it while travelling along the coast — Nice, Cannes, the inland towns — is a pleasure for anyone who enjoys procedural fiction.