Kardamili is inseparable from Patrick Leigh Fermor. Read him before you arrive.
Mani: Travels in the Southern Peloponnese by Patrick Leigh Fermor — The book that defined the place. Fermor arrived in the 1950s when the Mani was barely accessible and utterly itself, and his account of travelling through it — by foot, by donkey, on the hospitality of tower-house families — is one of the great pieces of English travel writing. It is half archaeology, half social history, half pure exhilaration at the strangeness of the world. The half that concerns Kardamili and the Viros Gorge is worth reading aloud while sitting at the village waterfront.
Roumeli: Travels in Northern Greece by Patrick Leigh Fermor — The companion volume, covering northern Greece. Not about Kardamili but soaked in the same sensibility. A natural sequel once you've finished Mani.
Between the Woods and the Water by Patrick Leigh Fermor — From an earlier adventure, crossing pre-war Europe on foot. Nothing to do with Greece, but the writing is so alive that it belongs on any Fermor devotee's reading list. Understanding why Fermor was special means following him across more than one journey.