Just before I left to serve as a missionary I was given a boxed set of paperback books that included James E. Talmage's masterpieces Jesus The Christ and The Articles of Faith, LeGrand Richards' fundamental work A Marvelous Work and a Wonder, and the LDS Church's Gospel Principles manual.
I read through Elder Richards' book easily enough. Talmage's books, although magnificent, were written in the grammar of a true scholar at a time when the average person's vocabulary was much larger and included words like pulchritude, abrogation, and annunciation. (See John Branyan's comical take on modern vs. historical vocabulary and grammar.) While I learned much in reading Talmage's works, the chore was a tough slog for my callow, simply educated brain.
Also included in the boxed set was a slender fifth book. To this day I still don't understand how or why this book was included in the set. Perhaps one of the authors was related to a general authority. The book read more like the findings of a doctorate thesis or a university research project. It was all about how a child's placement in the family permanently sets the child's personality. The authors prescribed methods for interacting with others based on their birth order among their siblings. While birth order no doubt affects each person, I still think the book smacked of pop culture mumbo jumbo and had little relevance for a missionary.
Another book I received was Spencer W. Kimball's The Miracle of Forgiveness. This was much easier for me to read than the books by Talmage or even Richards. Mind you, I studied all of these books while I also studiously delved into the scriptures and resources for learning Norwegian.
In the MTC we were also given a book titled Tools for Missionaries. It was commonly referred to by those in my mission as "Tull for Misjonærer." The Norwegian word "tull" does not mean "tools;" it means "nonsense" (at least in politically correct English).
It wasn't that the book contained no useful information. It did, however, seem heavily slanted toward missionaries serving in Latin American cultures. That probably made sense, since that is where the church was experiencing high growth. But many of the suggestions in the book were wholly unsuited to northern Europe, rendering many parts of the book irrelevant to us. (I still dutifully studied the book.)
I regularly read these various books while riding buses, streetcars, or trains, in addition to reading them in my apartment. If I had been a better missionary I probably would have looked for contacting opportunities while using mass transit instead of hiding behind my books.
Being somewhat of an introvert, I frankly hated cold contacting people in public. I had little problem talking to people if they initiated the discussion. I could (and often did) knock on doors all day long. I think this didn't bother me much because gaining admittance was rare enough to render it less threatening.
I spent a significant portion of my mission working in the mission office in various positions. Administration seemed to come naturally to me, so my skills were well used. Although we did traditional missionary work in the evenings, the hours I spent daily working in the office minimized the need to engage in salesmanship tactics, something I still avoid. (I very much appreciate Orson Scott Card's recent article on introverts in an extrovert church.)
My missionary son today uses Preach My Gospel, correlated manuals, and the scriptures for his main reference materials. In my opinion this compendium represents a vast improvement over the resources I used back in my day. The extrascriptural elements are written in straightforward language. They are generally relevant to missionary work and are flexible enough to be individually and situationally relevant.
Works like those by Talmage that I studied as a missionary can be wonderful supplements for those that wish to stretch their linguistic as well as their scriptural understanding. Each of us needs a better comprehension of what and whom we worship. But I am glad that today's core missionary library focuses on simplicity. The universe is a complex place. But many solid truths are rooted in simplicity.