WEBSITES:
Ask a Missionary is a question and answer website with a range of topics: guidance on calling, funding, selecting a mission agency, families on the field, training, and professional skills. The website also has articles and book recommendations on the same topics.
Syzygy, a British missions support organization, has a helpful page of questions and answers about becoming a missionary to get people started.
Velvet Ashes, a website designed to be an encouragement to women serving overseas, has a Leaving Home series which provides women planning an international move with weekly emails offering encouragement and advice, resources to help in the transition, and a community in the form of a Facebook group with others going through transition.
For individuals interested in ministering in Israel, the Shepherd's Light, a ministry of Calvary Chapel Tel Aviv, has on their website a series of videos which help build an understanding of the nation of Israel and how to minister there.
Ends of the Earth Ministries has a fifteen session video course, originally taught at Calvary Chapel Bible College, available for viewing on their website. They also have twelve audio training sessions on cross-cultural ministry and culture shock.
Preparing to Go contains some helpful articles and links to aid missionaries to find mentors, assess their readiness, get training, and explore their options for missions service.