It's definitely not a First Amendment issue, despite what the teacher's attorney said.
The teacher assigned The Freedom Writers Diary, a book about a teacher who is able to reach inner city students through writing, helping them grow and mature in the process. It was recently made into a movie--and yes, there are some graphic themes and language in it.
The teacher's supervisor (principal) sent her an email telling her not to use the book in her class. She did anyway: "They were reading, they were engaged. And then I read that email again, and I looked at my students, and I decided, I want them to read this book."
And for her going against the rules, she's been suspended without pay for a year and half--and promises not to return unless she can teach using that book.
I've stated before on this blog--it may not be smart for schools or districts to keep particular books out of classrooms, but it is legal. And since we teachers are public employees and not private contractors, we follow the instructions that are laid out by the elected school boards and implemented through the school administration. I'm sorry this teacher lost her job over this, but she defied specific instructions about curriculum.
If she was so adamant about her students' reading this book, she could have told them about it and suggested they check it out of the school library, where it sits on a shelf.
Full disclosure: I have a shelf of books in my classroom, and this book is on that shelf.