Javvin has just published two new quick guides: Unix Quick Guide and Linux Quick Guide, which serve as comprehensive yet portable references for all Unix/Linux users to fully harness the power of Unix features, functions and tools.
The highlights of both the Unix and Linux quick guide are listed below:  
•    A comprehensive yet portable Unix/Linux reference for every Unix/Linux user to harness the power of Unix/Linux features, functions and tools.
•    Unix operating system and Kernel architecture.
•    Historic chart of Unix distributions and popular shells deployed in Unix/Linux systems.
•    Unix/Linux filesystem structure and commonly used configuration files in Unix/Linux systems. Frequently used commands and tools for file and directory management.
•    Security risks and Unix/Linux solutions in the categories of data protection, system update, user management, Internet threats and more.
•    Frequently used commands and tools for user and group management, jobs and processes management, networking operations, system management and more.
•    Designed by experts with decades of experience in Unix/Linux operating systems.
The details of the Unix quick guide can be found at: http://www.javvin.com/unix-guide.html.
The details of the Linux quick guide can be found at: http://www.javvin.com/linux-guide.html. 
Javvin Technologies Inc., based at the Silicon Valley of California USA, is an industry leader to provide information products and marketing services to IT, networking and Telecom industries. Javvin products have been used worldwide by the IT, networking and telecom professionals. Top technology providers, such as Cisco, Juniper, Tellabs, Extreme Networks and many more… are using Javvin products for their customer training and marketing events. Javvin products and services can be found at www.javvin.com.
Javvin also has a free technical content site: http://www.networkdictionary.com, which provides high quality information for IT, networking and telecom professionals. It is also an open online community for people in the industry to get connected and share knowledge.