The Rest of the Bible: A Guide to the Old Testament of the Early Church by Theron Mathis available at Conciliar Press. I grew up Southern Baptist, and always prided myself on my knowledge of the Bible. I can still list all 66 books of the Protestant Bible in order to this day. It wasn't until I had to go to Catholic School that I discovered there were extra books in their Bible. It wouldn't be until years later when I converted that I learned that Protestants had removed the books and they weren't added by Catholics or Orthodox at all.
In fact, I often get asked by family members who are still Baptist, "What do you call those extra books in your Bible?" And, I must admit, sometimes I answer half-seriously and half-sarcastically, "The Bible," because they aren't extra to Catholics or Orthodox. They are simply a normal part of our Bible. However, as Mr. Mathis points out in his Introduction, in the early part of the Church, these were referred to as "The Readables." This is a much better response than I was giving, and the term gives a truer sense of what these books are, as opposed to terms such as "Apocrypha" or "Deuterocanonical." These truly are books that are beneficial for all Christians to read.
Each chapter is approximately ten pages long and provides you with a background/summary of the Scripture, how it is used in the Church liturgically (if it is so used), and/or what the Church Fathers had to say about it, also known as Patristics. The chapter sections on what the Church Fathers had to say was the most interesting and helpful to me. I have a great love for Patristics, and I believe that they understand the Scriptures better than anyone as they were alive close to the time when it was written.
This book is a very easy and understandable read. If you have read these books/sections in your Bible, then you will recognize many familiar passages and gain a better appreciation of them. If you have never read these selections in your Bible or these selections aren't in your Bible, then this book is a must-read for you. Tobit and the Wisdom of Sirach are two of my favorite of "The Readables," but you will find something beneficial for your spiritual life in all of them. So pick up this 5 star book to serve as a reading companion for you while reading the Bible.