Statista is a great source for global health data, public opinion on health topics, and other resources. It will often lead you directly to original data sources, thus saving labor.
This resource allows users to dive directly into healthcare and public health datasets. You can see the CDC's priorities in its choice of categories, such as vaccination rates and environmental health.
This hub has a huge amount of global healthcare systems and public health data. Country profiles and the annual World Health Statistics report are useful in a variety of contexts.
Health statistics are increasingly important in measuring the nation’s overall well-being. The Census Bureau provides accurate, detailed, and up-to-date statistics—covering people and business—relating to health in America.
The World Bank Open Data project provides easy-to-use access to a variety of development indicators (e.g., poverty, education). They have more advanced datasets as well, but this is the best place to start for new researchers.
An international consortium of more than 810 academic institutions and research organizations, ICPSR provides leadership and training in data access, curation, and methods of analysis for the social science research community.