There are many great ideas for student projects and assignments in this list from the New York Times. How about allowing your students to create infographics, storyboards, write a rap or song, make a news broadcast, or create a podcast?
This NPR article is fairly short, but gives an overview of several incidents of athlete protest, starting in 1969 with the University of Wyoming. This article was written before Colin Kaepernick's protest. It was written in response to the "Hands Up, Don't Shoot" protest by the St. Louis Rams.
Although Kaepernick himself doesn't speak in this video, students will be able to read quotes explaining his actions. The official statement from the 49ers management is read, and a brief commentary by a newscaster. It's useful for general background on what Kaepernick did and why he did it.
Muhammad Ali explains in a direct, personal, and powerful way, why he refused to serve in Vietnam. "I did not lose a thing," he says (by taking this stand). "I have gained a peace of mind . . . A peace of heart." This primary source would be great to show your students when you're studying the history of athlete protests or the Vietnam War.
This video briefly introduces the history of racial conflict in the U.S. in the 1960s, then shows video footage of Tommie Smith and John Carlos giving their famous black power salute on the medal stand at the Mexico City Olympics in 1968.
Eight athletes -- Kenny Britt, LeBron James, Johnson Bademosi, Derrick Rose, Reggie Bush, Andrew Hawkins, Brandon Meriweather, and Kobe Bryant -- explain, in their words, what led them to publicly protest what they viewed as injustice.
President Obama explains, in this video footage, that Kaepernick is within his constitutional rights by protesting. He also expresses empathy and understanding for those who served in the military and feel hurt and offended by Kaepernick's act of protest.
Discussing current events like pro athlete protests and racial injustice will evoke strong feelings from your students. It's important to know how to manage these discussions and assignments to keep the focus on learning and developing skills, and avoid situations where students feel uncomfortable in your class. This page from the Center for Research on Learning and Teaching links to discussion guidelines on various controversial topics (racial conflict, war, anti-gay speech, among others).