I got this one(on my kindle) before I was flying from NY to SFO for an interview. Couldn't have asked for something better to go through so quickly on the previous night.
Hardware, Red Hat, Debain/Ubuntu, General Administration, Common commands and utilities, shell and scripting, firewalls, routing, and much more was covered in depth. Overall a nice package. Worth a buy.
-By Patrick on www.amazon.com