If you only read one Schumacher biography, I'd recommend this one. The style is very flowing, using interviews and press releases from the time so you have a real idea of thoughts and feelings as they happened. It feels as though it was written in collaboration with all the people involved. There's plenty of insights from Schumacher, Ross Brawn, Byrne, Stepney and others.
I admire Christopher Hilton for being able to bring so many sources together and write the story in such a clear and readable fashion. He even manages to bring the races to life so you feel the excitement of the championships fought.