Firstly you shouldn't reward significant work achievements with a cheap book. That's tone deaf no matter what the book is.
Secondly if you do pick a book, you can at least try to make it relevant to someone's actual professional competence - something useful, but not insultingly peppy.
Thirdly if you're going to do that, you can ask them what they want, in a way that indicates you value their competence and opinion.
Gifts and rewards are all about social signalling, hierarchies and statements of relative value. The messages are understood whether or not you're aware you're speaking that language.
If you get it wrong, it's not just demotivating for the person, it's demotivating for everyone else too.
And no, you don't have to be super-serious about it. Jokey gifts are fine, although riskier than something straight. If the culture can take it, they're a good choice. But you have to be very sure that is the culture.
