I would use “planning skills” for the content of this book. As for the title, your suggestion “The Power Of ～” would nicely fit with this phrase.

If I am not mistaken, the title of a book in the language other than the language of the document the book is mentioned in is not supposed to be translated, unless the book in question has already been translated in the language of the document and it is that very translation, not the orignal version, is mentioned in the text. For example, if the book is mentioned as one of the source of information in the reference part of a research paper, it should be listed exactly the way it was used: if a researcher used an original Japanese source and then mentioned the infromation from that source in his research in English, the source should still be listed in Japanese. It is possible, however, to post the transliteration of the title in the parenthesis. If the title is mentioned in the body of the text, you can transliterate it and then make a footnote stating the original Japanese title and stipulating "(in Japanese)" - unless there exists an English translation of the book and it is exactly that translation that is mentioned in the document.

I agree with Oikawa san's suggestion but I would like to suggest a shorter version because it's for a book title. I think "The Powerful Planning Skill" would work as well. I put "the" because 段取り力 seems to be a proper noun the author invented.