It's difficult to suggest a level for this book. Each article is written both in Japanese and in English (with romaji). So, definitely beginners could read and learn a lot, but I think the topics covered are more for the upper beginner level.
Using simple, but real-world conversations, the authors take one neglected--but certainly important--grammatical or cultural point.
As you can see with the scans, the right page is in Japanese and the left is in English with romaji. This is certainly nice if you have a Japanese tutor. Your tutor/teacher can read the Japanese and explain any nuance not mentioned in the book.