You may not have heard of the Linux Professional Institute (LPI) or its professional certifications, but they're becoming an important part of proving professional competence in the Linux operating system. That aside, LPI Linux Certification in a Nutshell is a fantastic introductory Linux book, well suited to introducing a curious newcomer to the environment and bringing an intermediate user up to expert status. The book is organized around the LPI's published standards for two Level 1 exams (exams 101, which deals with key commands and file-system concepts, and 102, which places more emphasis on hardware, networking, and shell scripting). The organization works well even if you're not specifically preparing for either exam. LPI Linux Certification in a Nutshell assumes nothing in early chapters, going so far--to cite one example--as to walk readers through the concept of commands with parameters separately from the concept of commands alone. Later, the pace picks up, and strategic advice is substituted (such as how to partition a disk for maximum speed and reliability) for "type-this" instructions. Throughout, the book makes effective use of O'Reilly's time-tested and remarkably clear format for presenting Unix commands and configuration files. Each chapter concludes with a series of exercises designed to help you discover behaviors on your own, and includes the practice questions you expect in a test-prep aid.