God works in different ways, but it is the same God who does the work in all of us.
1 Cor.12:6 New Living Translation
Many ways to serve
You can be sent out on a short or long term basis. Maybe you want to preach the Gospel, train disciples. You may prefer development work. And don't forget, offices need staff. There are many opportunities (link to Opportunities, or embed in this page in a table) and no doubt there is one that fits you!
Orientation
As an orientation you could visit a mission post and offer your practical help for a couple of weeks. Or join a group of youngsters and serve an (overseas) mission project. A number of mission organisations organize such trips: Livingstone, Youth with a Mission, East Europe Mission, Athletes in Action, Children's Relief and more.
Training
The job you prefer and the place where you'll work will have a major influence on your preparations. Some jobs demand a higher education. People and their culture can be so different from your own that you have to learn about them before you leave.
Working area
Almost all mission organizations have defined their tasks and the countries where they work. Some concentrate on church planting only, others give practical aid. Aid may sometimes be the only way to work in a country, as some countries don't allow evangelism and are closed to Christian workers.
Three work areas are highlighted on the following pages:
Church planting
Aid
Supportive work