I have to admit when I first got this book I thought it was going to be one of those massive (500+ pages!) dry textbooks I can hardly finish. I was pleasantly surprised! Helyer's writing style is clear, engaging, and smooth. I haven't read much about Jewish literature of the 2nd Temple period, so I'm glad to own this book as a resource. I'm sure I'll consult it quite a bit in my NT studies, especially since there's a Scripture index in the back as well as a topical index.
In case you were wondering, Helyer discusses most of the important Jewish writings, including those found in the Apocrypha, the Pseudepigrapha, and the Dead Sea Scrolls; he also interacts in detail with Philo, Josephus, and the Mishna (along with others). He typically gives the dating of each work, the outline, the main contents, and what it has to do with our studies of the NT. The structure is helpful and easy to read/reference.
I do wish there was a summary chart of each Jewish writing (dating, main themes, etc.) in the appendix so one could have a quick-reference guide. However, the book is valuable as is. It's a very long introductory survey, but it is one I'm glad to own. In fact, Helyer's work has led me to start reading some of these Jewish writings themselves (i.e. I've already read Susanna, Ben Sira, and parts of Tobit). I do recommend this book.