Btw, I'm a true crime head too.
@The HONORABLE SKJ can probably drop some good recs too.
From Altar Boy to Hitman is good. It'll paint a picture of the race wars in Cali's bings during the 70's from an early La Eme member's perspective.
Black Brothers Inc. deals with Philly's Black Mafia during the 60s and 70s. They really thought about killing Lou Rawls at one point.

It talks about the Hanafi murders too which I think should be required reading for anyone with an overly positive view of the NOI.
No Beast So Fierce by Eddie Bunker who was Mr Blue in Resovoire Dogs. It details his life behind bars before the race based gangs came into their own. Danny Trejo was locked up with him and runnin with Southern Mexicans and mentioned a couple times. It touches on George Jackson for a bit too.
Five Families is a good Italian Mafia history book.
House of the Dead by Fyodor Dostoevsky is based upon his experiences in a Siberian Prison Camp
The Almighty Black P Stone Nation Rise and Fall is good detailing the history of them in Chicago and Jeff Fort. It examines the El Rukn phase too along with a little bit Larry Hoover and the GDs.