The Everyday Catholic's Guide to the Liturgy of the Hours:

The Everyday Catholic's Guide to the Liturgy of the Hours By: Daria Sockey
Non-fiction: religion, NYR 115 pages
Book Count: 34

This book goes over the basic things you need to know in order to pray the Liturgy of the Hours or the Divine Office.  (As for some reason both the book and digital forms of the breviary don't bother to include this information in them. The book forms even have other books to buy just to know where in the book you should be reading each day.)  It covers: what it is, why pray the hours, resources, a break down of the hours and seasons, and common issues and problems people have with this method of prayer.  As you can tell from the page count this book is a quick read, but it does a good job as a starting point and the listing of resources included is helpful for people that want more information.