Michael, for your WWI propaganda section, if you can lay your hands on it, you'll probably want to at least read "The Eagle's Eye," by Courtney Ryley Cooper (story and background by the William J. Flynn, whose name you no doubt recognize from his acclaimed Secret Service stint at that time). It's not just insight into the era itself, but it's clearly the "playbook" for WWII propaganda twenty years later. And it's a fun read, to boot.