Algebra is a stumbling stone for many of our pupils. It is also a branch of mathematics that is important for many other areas of mathematics. Jinfa Cai and Eric Knuth have edited a new book on “Early Algebraization” that has recently been published by Springer. The book belongs within the series “Advances in Mathematics Education“, which involves many important books (most of them outrageously expensive, I’m afraid). The main editors for this series are Gabriele Kaiser and Bharath Sriraman.
The table of contents is freely available for download, and so is the preface and some sample pages. The book has three parts, including curricular aspects, cognitive aspects and instructional aspects of algebra in school. Some of you might be lucky enough to be able to read the book online, others have to dig deep in your pockets and buy the book. If you are interested in algebra (and particularly from a research perspective), I think the book should definitely find a place in your shelves. If you cannot afford it, the introduction is very readable, and it gives a nice overview of the book.
Reidar Mosvold 
Early Algebraization: A Global Dialogue from Multiple Perspectives by Jinfa Cai and Eric Knuth is a must read and have for every math instructor wanting to understand curricular, cognitive, and instructional perspectives. I recently obtained a copy from the publisher. Although I am still in the process of reading it, the information and research present from the likes of Asia, North America and Europe made me realize that this is a global issue. Although the book focuses on the development of students’ algebraic thinking in the elementary and middle school grades.