Valid, certified, original and readable! 

Take time to prepare these, it would be a pity to have to postpone or cancel your volunteer work because your documents are not in order.

You can normally find all the practical information on the website of the foreign affairs of your country: visa conditions, needed documentation and address of the embassy. 

Talk with your sending information, they can inform you! 

Useful link: Check if you need a visa with your passport for your destination : https://www.passportindex.org/