Who or what is the population you want to study?
When? What is the time period you want to study?
Where? What is the geographic location you want to study?
Remember: You might need to be flexible here. Not all data is gathered/published/made public.
Then, ask the following:
Who is collecting this data? Where can I find it?
*Important to remember: most data sites are aggregators. Content will vary, and you might need to drill down to get what you need.
Government Agencies, Intergovernmental Organizations, and Non-Governmental Organizations (NGOs)
Library Resources (combine private sector and public data)
Find more open web resources linked in the guides below.