Decolonization is not a Metaphor - information - PDF, academic paper. This is heavy, but in my opinion, it is nigh-on required reading about decolonial theory and how to put it into practice.
Native Land - information - this site is an interactive map of some of the parts of the world that are most heavily damaged by ongoing settler-colonialist activities. It displays information about the Indigenous people who were in these places since time beyond memory. For those of us who are not Indigenous to a region, it is a very useful tool for understanding who our presence has displaced and impacted. It is not just a history lesson; it is also an effective jumping-off point for learning more about local efforts we can participate in to work against the continuing harm of colonialism.
LAND BACK! What do we mean? - information - a useful, introductory-level resource about the Land Back movement and what the phrase can mean to various Indigenous communities and causes.
A People's History of the United States - information - this is the complete text of the work by Howard Zinn, offering a pointed counter-narrative to the typical story told of "history" in the US. It is a long and heavy read, and by no means an "authoritative" work (there are many different perspectives of that history and this is only one, a fact attested to by Zinn himself) but it is nevertheless an extremely eye-opening book.
Real Rent Duwamish - actionable - The Duwamish are the original, rightful caretakers of the area around what has become the city of Seattle. They are not formally recognized by the United States federal government and are severely impacted by the legacy of extremely wealthy companies extracting profit on their land. Supporting the equity, recognition, and return to stewardship of the tribe should be a priority for anyone living in the region.
Faculty/Staff Page for Robin W. Kimmerer - information - Dr. Kimmerer is a very notable voice for Indigenous tradition and wisdom, especially in the realm of ecology. Her book Braiding Sweetgrass is also an excellent resource; it (among many other projects) are listed on the linked page.
Worldwide Story Structures - information - a fascinating collection of ways in which stories are told in various cultures and frames of reference. Excellent antidote to the "conflict is the core of narrative" poison often found in and around white supremacy culture. Humans relay information and wisdom in many, many ways; this is a great look at how some of those forms and structures work, and a good jumping-off point for exploring more ways of relating to each other in the form of shared culture.
How to be a Good Relative - information - an excellent zine that covers some solid, practical advice for being in good relationship with Indigenous people and communities. It's also just generally good advice.