Hitler was egomaniacal I don't think he would have a change of heart, but instead use any information too alter the outcome.
But if you're going to send a book to one of the worst people in history it's gotta be one of the worst books in history. Just gotta find the right age to send him The Game: Penetrating the Secret Society of Pickup Artists by Neil Strauss. I need AI to get to the next level so I can see how this might play out.
We're in the timeline where he was stopped and had to kill himself, not sure I really want to give him any pointers about how to further his agenda but slightly differently and avoiding some tactical mistakes. I don't think he's going to take from the book that his world view was wrong or that for the good of Germany he should abandon his goals.
That book would inform him that if he starts a war to expand Germany, the actual result will be to make Germany a lot smaller, divided into a liberal and a communist state (until the communist one gets absorbed into the liberal one), and him remembered as possibly the worst person to have ever lived.
Pretty sure he'd only wonder what he did "wrong" during his years in charge, if the book doesn't dive into that detail, and try something different. He'd probably feel even more infatuated with his idea of "glorious aryan german nationalism" if the book mentions, even by passing, that the werhmacht quickly beat France into submission.