Push: A Novel (Paperback) by Sapphire
As everyone (I think!) knows, this is the book that the movie Push is based on. It is an excellent novel, told from the perspective of Precious Jones, an abused teenager who has been kicked out of school because of her pregnancy (this takes place in the mid 80s).
With a deep-seated need to better herself, Precious begins to take classes at an alternative learning center, where she finally (at age 16-17) learns to read.
The life Precious has led is horrific and heartbreaking, but her spirit is amazing. Still, the story is not a happy one, but rather can be considered deeply inspiring.