As a potential teacher going overseas for the first time or as an experienced teacher looking to move to another country, we must encourage you to find out and research as much as possible about the country you are going to. Canada obviously has different visa requirements than South Korea and likewise, France has other issues with work applications than say, the Czech Republic.
Most countries in the world have embassies and their locations are listed in the link we have provided for you here. It's the best list we have found. It is vital that when you accept a job in any country, you find out where the nearest Embassy, Consulate or Consular General is.
If you live in the same city, that's great. For example, if you live in Vancouver, Canada, want to teach in China and need a work visa, then you can apply directly to the Chinese Consulate in Vancouver. However, if you do not live in a city that has an Embassy, you will need the contact info of that Embassy for specific mailing/couriering instructions.
Keep checking this page for helpful hints on applying and obtaining work visas! We will be soon providing detailed, concise instructions for South Korea, China, Taiwan, Spain, Japan and other popular destinations!