Here is a list of books that I have read and can recommend.
Agile Estimating and Planning: a great book not only on Product Planning, but also User Story writing and mapping.
Agile Software Development with Scrum by Ken Schwaber. This is one of the true classics, where Scrum really started. Short, punchy and essential, with some good war stories.
The Art of Agile Development by James Shore. Long and intense, this is a solid introduction to Extreme Programming. Includes some good coverage of TDD.
Succeeding with Agile: Software Development Using Scrum by Mike Cohn. An influential and in-depth coverage of Scrum, especially on the organisational change management challenges in implementing Agile in an existing organisation.
Leaders Eat Last by Simon Sinek. An excellent rethinking of the role and purpose of leadership and management in modern organisations: the job of a manager is not to boss people around, but to protect and look after the tribe.