This book is two hundred years old, and feels as though it could have been written yesterday. This is Austen's gentle sendup of the Gothic novel craze of her day, and introduces Catherine Morland, a girl who did not seem to be born a heroine - her mother did not die at her birth, her father "was not in the least addicted to locking up his daughters", and Catherine herself displayed more tomboyish tendencies than the gentle nurturing arts of the heroine.
At the age of seventeen, Catherine gets a trip to Bath with some family friends. While there, the airheaded Catherine makes some new friends and falls for Henry Tilney, a young gentleman who is quite aware of the social silliness surrounding them. He and his sister Eleanor invite Catherine to their home at Northanger Abbey, and the novel-devouring Catherine is excited to be on a true Gothic adventure. (The scene where they are traveling to the abbey is extraordinarily hilarious, as Henry uses the opportunity to spin a frightening yarn to Catherine, and stops it just at the suspenseful part.) What she finds, however, is far more mundane - and petty - than she had expected, and she learns, or at least begins to learn, that fiction and reality are often two very different things.
As with the rest of Jane Austen's work, the humor is in the phrasing. Lines such as "A family of ten children will always be called a fine family, when there are heads and arms and legs enough for the number," are funny only if one is used to verbal humor. If that is not you, avoid this novel as it will seem banal. If, however, you are good at reading between the lines, the absurdity of the situations in this novel will almost certainly lead to laughter.