The BYU Hawaii missionary preparation course recommends several resources for preparing missionaries, most of which are freely available online. They include:

• The official Preach My Gospel manual (PDF)
• The LDS CES Religion 130 "Missionary Preparation Student Manual"
• The approved missionary library: Jesus the Christ (James E. Talmage), Our Search for Happiness (M. Russell Ballard), Our Heritage (PDF), and True to the Faith (PDF).
• The First Presidency letter Missionary Work in the Ward

For instructors, you may also view the Fall 2008 Course Calendar with a one-semester reading schedule (the syllabus is also available, with class rules and grading policies, as well as a simplified calendar).

A diverse mission preparation class. Discusses the priesthood, major world religions, mainstream Christian doctrines compared to LDS doctrines, evidences for the Book of Mormon, attributes of the Savior, the standard works of the church, teaching by the spirit, and moral worthiness.

It is hard for some missionaries to transition back to "normal" life after finishing their mission. This article discusses principles designed to help ease that transition.

Some returned missionaries have found on-line planning tools, like that found at RMDailyPlanner.com, helpful in transitioning from a structured mission environment to a non-missionary lifestyle.

There are many questions that parents of returning missionaries have. This article discusses some of the common themes that leaders have found when talking to anxious parents of soon-to-return missionaries, and offers suggestions on helping both parents and missionaries make the transition.

Cumorah.com has numerous missionary resources, including many interesting statistics and a book about principles of effective missionary work.