Pretties and Uglies are books of the Uglies trilogy by Scott Westerfield. The story is futuristic, but I don't know if it can be classified as sci-fi.
The story centres around a nearly-16 year old girl, Tally, and her friend, Shay. In their world, people are called uglies until they are 16 years old, when they are all given plastic surgeries to make them all look beautiful (hence they call them "Pretties"), and go to live in the nicer part of the city.
The surgeries were intended to settle disputes, but it turns out that the surgeries cause brain damage that makes them unhappy, etc.
I don't know about the rest--they used to have it here, looks good. May try to get it sometime later.
The books are also followed by the third book in the trilogy, Specials (after the "Specials", who are more or less evil Pretties). There is also an additional 4th book, Extras, due to be out later in the year.
Is that the truth is ."
~ Lemony Snicket