Now that you've flooded Instagram with photos of black squares, it's time to hunker down for some real activism.

If you're a white person, you're sitting on top of about four centuries of institutionalized racism. In the wake of George Floyd's murder by police and countless Black Lives Matter protests across the nation, it's time to show up—with your body, with your voice, and with your brain.

It's no longer OK to just be "not racist." You have to be actively anti-racist, and there's a growing list of resources available to help you do just that. And what better way to learn than by sticking your nose into a book?

Below, we've compiled a list of 10 books—many of which are bestsellers—by Black authors that will give you a much more thorough understanding of how deeply racism runs in the United States.

Black Feminist Thought by Patricia Hill Collins

In this 1990 book, author and academic Patricia Hill Collins takes a deeper look at the works of Black feminist thinkers like Angela Davis, bell hooks, Alice Walker, and Audre Lorde.