Thomas Howard has given the world a wonderful gift in his beautiful little book If Your Mind Wanders at Mass. Even those whose minds never wander at Mass should read it. Howard aptly leads the reader through a step-by-step tour of the Mass, pausing along the way to explain the heavenly significance of each minute detail of the liturgy.
This book would not be particularly appropriate as a primer for someone who had never been to a Catholic church before, but Catholics and non-Catholics alike who have always wondered why Catholics do things the way they do will find their appreciation of the Mass greatly increased by reading this slim volume.
I read this book during the summer and then lent it to my grandma, and it was so good that I'm going to read it again now that I've gotten it back.