It is a demanding book, but the difficulty lies in its size and its names, not in its plot. The story fits in a few lines: a father, a landowner and buffoon, has three sons he did not raise and is killed one night; one of the sons is arrested, tried and convicted, although the murderer confessed to Ivan and hanged himself. The rest of the book is what each person does with that crime.
Its length is mastered by units of scene. There are four parts, twelve books and an epilogue, with the preface "From the author" and 96 numbered chapters, and each book has a clear axis: the meeting in the cell, the brothers' conversation in the tavern, Zosima's last afternoon, Mitya's chase after three thousand rubles, the trial. The first obstacle is the beginning: the preface and Book I are prehistory told by a town chronicler, who warns that the hero's biography is one but spans two novels, and even gives the delicate reader a pretext to drop the book at the first episode.
Names are the second barrier, because each person has more than one. Alexei Fyodorovich Karamazov is Alyosha; Dmitri Fyodorovich is Mitya; Katerina Ivanovna is Katya; Agrafena Alexandrovna is Grushenka, in her popular diminutive. Smerdyakov was baptized Pavel, and everyone calls him by the patronymic Fyodorovich. Whoever stumbles over a name can follow the patronymic: the three brothers are Fyodorovich, sons of Fyodor Pavlovich.
Two passages deserve more attention than the rest: Book V, in which Ivan sets out Rebellion and The Grand Inquisitor, the novel's most complete attack on a harmony paid for with the tears of a child, and Book VI, which answers with Zosima's life. Dostoevsky noted, after finishing the book, that the whole of it is the answer to the legend of the Grand Inquisitor. It is worth reading the two books without haste and in sequence, because the second answers the first.