Take a look at "I Was Right On Time" by Buck O'Neil. It's his autobiography.
O'Neil is (was...I still can't get used to the fact that he's dead) the greatest story-teller in baseball, and this book is chock full of good ones. He talks about Satchel, Cool Papa, Turkey Stearnes, El Diamante, Josh Gibson and a ton of other Negro League guys, as well as his experiences playing, coaching, scouting and setting up his Negro Leagues museum.
This is a GREAT read. Check it out.