I'm rereading a favorite at the moment (Byzantium by Stephen Lawhead). I can read a fiction and a nonfiction at the same time but not two fiction novels at the same time. I get too deeply immersed in the characters and story and I would find it too distracting and disorienting to switch gears mid story. I generally read at least a couple hours a day and tend to go through a novel a week on average. Barnes & Noble loves me