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.