There was a recent book[1] by Cat Jarman called The River Kings that discusses the Vikings’ expansive trade with the east. It was decent and was quite popular after publication.
Also related are Ahmad ibn Fadlan's writings, a 10th century traveler from Baghdad who described the Varangians, Swedish vikings who traveled to modern-day Ukraine and Russia, who also ended up in the Byzantine army (or something like that, see https://en.wikipedia.org/wiki/Varangians). Eaters of the Dead, a book by Michael Crighton combines those writings plus the story of Beowulf into a book, which was later turned into a film, The 13th Warrior.