MAC OS X unleashed - John Ray

Mac OS X Unleashed is a complete guide and reference for Mac OS users. The power of OS X is largely in its underlying BSD implementation. For an average Mac user, experiencing a command line for the first time can be an unpleasant experience. This book will take the approach of demonstrating familiar actions and tools, and then provide the equivalent information within the BSD environment. For advanced users, this book will cover system administration ranging from advanced configuration of FTP servers, SSH tunneling, to installing secure E-mail and Web servers. The progression of the text is designed to move from simple "using" topics through advanced configuration - making it easier for beginners and experienced users to find what they're looking for.

In short, Mac OS books have never had to deal with issues beyond the Macintosh GUI. This book will bridge the gap between the user interface and the BSD subsystem in a way that is accessible to users who are unfamiliar with UNIX and other multi-user systems.