This is a dynamic and intentionally short collection of resources I think are useful for understanding space governance.
This 2021 article by the Wilson Center gives a good overview of the global legal landscape of space, including UN space treaties and organizations.
The Outer Space Treaty (1967) is the common international basis for space law. The UN is set to discuss an update next year.
The Artemis Accords (2020) is a set of principles for the usage of outer space, written by the United States and signed by over a dozen other countries (but not China or Russia).
Long Term Future:
The space governance profile on 80,000 Hours (Moorhouse 2022) is a concise summary of space governance from a longtermist perspective.
Eternity in six hours: Intergalactic spreading of intelligent life and sharpening the Fermi paradox (Armstrong & Sandberg 2013) is a good introduction to how civilizations can spread influence beyond their home worlds. (Paper, 35 pages) It was expanded here in 2018.
Astronomical Waste (Bostrom 2003) describes how reducing existential risk is more important than speeding up space colonization. (Paper, 10 pages)
Long Term Trajectories of Human Civilization (Baum, et al. 2019) discusses the paths that human civilization can take during the entire future time period in which it could continue to exist and posits that there are actions we can take now to significantly improve the future. (Paper, 34 pages)