Where can I find a comprehensive and detailed technical software manual for OS X? Are there books written for OS X (particularly the most current version) like the hundreds of thousands written for Unix? I'd like to know about the command-line utilities and the locations of system settings in text files. Unfortunately, the books you see coming out of O'Rielly have phrases like "For Dummies," "Pocket Guide," and "Learning" (shudder) in their titles.

Does such literature exist? I'm particularly interested in learning which plists control which system settings, but having usage examples of OS X-specific command line utilities and a list of differences between OS X and Unix (from a technical perspective) would be even better. Being able to manage my system configuration from the Terminal would be a lot more fun than from System Preferences... at least for me!
The Missing Manual series is pretty comprehensive for the whole OS, though they don't cover shell commands deeply. 

The Mac OS X Command Line: Unix Under the Hood covers more of the specifics you are looking for. 

Keep in mind that there technically is no difference "between OS X and Unix." Mac OS X IS a Unix