Bradman's place in the game of cricket is immortal, and this book is one of the great manuals for learning to play the game well.
Its focus is more on batting, as that is where The Don was at his greatest, but there is much useful discussion of bowling, and a great chapter on why the ball swings. Perhaps the weakest chapter is on captaincy, rather surprising as Bradman was a brilliant captain. For a good book on captaincy, see Mike Brearley's "The Art of Captaincy."
If you want to learn to bat like the greatest batsman, based on his own techniques, this is the book for you. Combine it with his video "How to Play Cricket" (based on his 1934 film) and you are in excellent shape.