Huckleberry Finn is the story of a boy with the same name, almost in a sort of sequel to Tom Sawyer. Huck is mischievous and practical, and starts his own adventure after running away from an abusive father, and "civilized" society. Huckleberry Finn, is renowned for its controversial content, for staring down discrimination and prejudice straight, and putting the early 19th century in a harsher light. Huckleberry Finn is both hilarious and uplifting, yet a testament to the dark side of humans. In short, it is indeed a novel, worthy of being named a classic. 
 Huckleberry Finn is a great adventure story at its core. Huck goes through many journeys and little episodes on his adventure down the Mississippi River. He meets people in feuds, robbers, frauds, and other questionable characters. He's compassionate, yet not naive - a quite agreeable and amiable character. By his side is the slave Jim throughout much of the book, and the two build a bond transcending society rules; the journey - more specifically raft is a sanctuary for them in a prejudiced society. Without being obviously moral, Twain condemns society's poor view of blacks and builds small stories of faith and trust subtly. 
 Huckleberry Finn also excels in humor. It is ridiculously funny at some points, and brings light to some scenes. Some say the dialogue is hard to get through, but it adds realism to the story. Also, I would highly suggest getting an annotated version of the novel if it is hard to read - I did and it helped a lot. 
 Hence, Huckleberry Finn is an enjoyable novel of historic value. Don't judge the novel quickly, because the book only gets better towards the end. Great book for class.