The Brother's Karamazov is generally considered among the best books ever written by mere mortals, and in my opinion it is well deserved of the distinction. Being unacquainted with Russian (and perhaps Russia generally), and with an author as idiomatic as Dostoevsky I can't overstress the importance of a decent translation. Mine is the recent translation by Richard Pevear and Larissa Volokhonsky, which in fact won the PEN/Book-of-the-Month Club translation prize in 1991. Having read a couple books by him before, I can note that Dostoevsky can be idiomatic, colloquial, and perhaps even redundant in places. Take for example this line from the author's introduction:
"Being at a loss to resolve these questions, I am resolved to leave them without any resolution."
Certain translators will cringe at that sort of thing, feeling it their duty to make Dostoevsky more palatable to our modern sense of grammar by busting out the thesaurus and shaving off seemingly redundant clauses. The problem with this, however, is that there is a sort of gait of thought that Dostoevsky had well developed by this, the last book of his career. The spacing of the active elements of the thought are given almost a rhythm, I find. As a poet uses syllables, so does Dostoevsky use thought. And all that elegance can be cut to ribbons by translators who feel it their duty to protect the reader from how the book was actually written. This is a problem that Pevear and Volokhonsky are thankfully not afflicted with. These two also provide a highly informative introduction and footnotes that provide fluid descriptions, not only of the contents of the book but the context of Dostoevsky's life.
At any rate, The Brothers Karamazov is a book that is almost too big to describe, but the story is largely about (unsurprisingly) the brothers Karamazov. I shirk from describing any of them with mere adjectives because of the sheer depth of the characters, it would be about as insulting as if one starting running around applying epithets to one's friends and neighbors.