I work for a nonprofit organization and we are establishing a policy platform that will house research and policy reports, data, articles, etc. What government data can we include on our platform that does not require prior permission or a formal contract.
It depends on what country you're in, and which level of government produced the work. In the US, all works produced by the federal government are in the public domain by law and can be used for any purpose: http://www.usa.gov/copyright.shtml. Works produced by US state and local governments may or may not be copyrighted; it depends on the jurisdiction (for a discussion of this see this presentation: http://www.ncsl.org/documents/lrl/Copyright-Conundrum-2014.pdf).