For mystery readers, give Jefferson Bass a try. Jefferson Bass is a pen name for two men who write together. One of them, Bill Bass, is the man who started the Body Farm in Tennessee. Anyone who likes CSI type things should really like him.
For a glimpse of women's issues in the mid-east, try Jean Sasson. She writes excellent non-fiction about women's rights in Saudi Arabia.
For a look at a different way of life in America, try The Last Frotiersman by James Campbell. It is an amazing true story of life well above the artic circle.
The authors mentioned earlier are all great, too. I just wanted to bring up a few that had not been mentioned. The list of great books could go on forever. I love seeing other people's ideas.