Austen began writing by writing poems and plays and stories that entertained her family - and she could be pretty dirty and slapstick. Lady Susan was her first full novel (although by modern standards it's a novella). It's written in epistolary form (that is, as a series of letters). Austen's first draft of Sense and Sensibility was called Elinor and Marianne, and it was also an epistolary novel. While I don't know why Austen changed the form of Sense and Sensibility, I do know that the epistolary form in Lady Susan has pros (hearing Lady Susan talk is endlessly entertaining) and cons (the form is, by it's nature, limiting, and Austen's other voices don't come through distinctly).One reason to read Lady Susan is to see how an author like Austen can improve her craft over time. Look at the voices in Pride and Prejudice. A letter by, say, Mrs. Bennett would not seem remotely like a letter from Charlotte Lucas. You would immediately be able to tell which character wrote which letter without so much as a glance at the signature. Alas, with the exception of Lady Susan and her friend, Mrs. Johnson, everyone in Lady Susan sounds pretty much the same - nice and boring. Luckily, we get enough of Lady Susan that the book as a whole is not boring in the least.