I highly recommend anything by Mumia Abu Jamal. I remember listening to his broadcsts from prison through Democracy Now probably fairly close to my own political awakening. I've been fascinated by the Black Panthers ever since. I love their leftism, sense of everyone on earth's common humanity, dedication to political education as much as taking care of basic needs like children's breakfast. It also covers the split, which has been at times confusing for me to sort out. 

He calls it a failure in its aims, but also recognizes finally its legendary status - and says something like it could rise again.

As he says:
"The Black Panther Party may indeed be history, but the forces that gave rise to it are not. They wait for the proper season to rise again."