These books, publishes in 1978, 1981 and 1986 are a classic of teenage literature, influencing many modern authors, including China Mieville. The stories revolve around the Borribles, who are essentially homeless children who become immortal homeless children after some time away from adult company. The books have a strong anti-authoritarian theme, with a recurring enemy being the corrupt police. The books have been the subject of some attempts to have them banned from schools, since the strong violence and anarchist themes were considered controversial.
By modern standards, the books are acceptable and a good rollicking fun, as the Borribles in the first book break into the secret bunker of the ratlike Rumbles, kill all of their leaders and steal their treasure. In the second book, it is Borrible against Borrible, as the break-out of Borribles kept captive in a mine by the Wandsworth Borribles is engineered. Finally, in the last book, the police are the enemy as the Borribles cross London to bring a Horse to freedom. The books are progressively less light, with the last book entailing a discussion about betrayal and causes worth dying for.
I can't recommend these books enough to adult readers who haven't read them. You might want to read them yourself again before giving them to very young teenagers.