The Vinland campaign is in the style of the Icelandic sagas, specifically the Islendingasögur or "Family Sagas" (which include Njal's Saga, the Laxdaela Saga, and others). Reading at least a few of the original sagas is strongly recommended, though not required. Though they have heroic and supernatural elements, the Islendingasögur are primarily historical tales about real people. I will want to arrange the sessions some to highlight this. The power level is at the high end of the historical sagas. The PCs are not superhuman, but should soon become reknown figures in their community, and may take on monsters like ghosts or wendigos -- though with trepidation. There is a lot of roleplaying, with emphasis on the cultures and relations between them.
The peculiar feature of this compared to many RPG campaigns is that the PC's are not adventurers. True to the sagas, the PC's are participating members of their family, homestead, and community. They have ambitions to marry, acquire land, and so forth. However, also like in the sagas, they are also likely to be active in viking raids, trade expeditions, feuds, quests, and so forth.
Adventure possibilities span a wide range: