Here's the link to Gospel Principles Lesson #33 Missionary Work.
I tried to find articles relating to full time missionary work and
the preparation in accordance to that as well as member missionary work. Here are my favorites.
President Kimball's Vision of Missionary Work- President Kimball talked a lot about missionary work so President Benson summarizes his words into four basic areas: Sacredness of Souls, Faith, Personal Goals, Accelerated Missionary Activity.
How to Prepare to Be a Good Missionary- Elder M. Russell Ballard does a Q&A on ways to prepare.
Be a Missionary All Your Life- Elder Quentin L. Cook gives four suggestions on how to be a missionary always.
Becoming a Missionary- Elder David A. Bednar mentions the difference between becoming a missionary and going on a mission.
The Essential Role of Member Missionary Work- Elder M. Russell Ballard again this time talking about the importance of our roles as members of the Church of Jesus Christ of Latter-day Saints.
Senior Missionaries and the Gospel- Elder Russell M. Nelson talks about the important role of senior missionaries.