This short book was actually by Banksy himself. But there exists a newish, second edition of a very-worthy bio. Fascinating and highly recommended. It describes the past 2 decades of the emergence of street art as a valued commodity (Banksy is very wealthy and could easily have been wealthier) as well as the meaning behind various street art stylings. There is also a new graphic novel about him, written by a pair of Italians. Note that his car is behind glass in Ely Place.