I have purchased over a dozen books about Drupal, and this one ranks among the top. It truly focuses on "The Essentials" of Drupal 7, as the title promises, and organizes its subjects in an impressively logical order. For a bonus, the author/publisher's website provides more than 40 tutorial videos, an impressive array of articles for developers, and an up-to-date blog.
The book is especially appropriate for beginner-to-intermediate Drupal developers. Several other Drupal books about Drupal 7, or with Drupal 7 sections, seem to have been published too early to provide accurate and complete information about Drupal 7. In contrast, this book is quite up-to-date about version 7's changes and new functionalities.
The book is a must-have for people creating news and documentation sites and portals; the author includes extensive practice exercises developing two mock sites--a "Documentation" site, and a "News" site. Specific guidance about these two types of sites are lacking in most other Drupal books.
The book's only weakness (English version) is its lack of having been adequately proofread. There are many grammatical errors. However, because because of how informative and compelling the book is, and because the author and publisher are Swedish and the translation seems to have been done digitally - I was able to forgive all the typos and make sense of most grammatical errors. Being patient with these translation glitches will pay off for you.
While this book is not as extensive and complete as the must-have "The Definitive Guide to Drupal 7," nor as advanced as "Drupal 7 Fields/CCK" -- I heartily recommend adding this book to your library and visiting its Website. You will have a top-notch basic reference book with hours of related video lessons.