I am reviewer on this book, , and here is what I say on Amazon about it:
The book talks about every aspect of Hadoop administration: choice of hardware/software, installation of Hadoop and all the tools, Pig, Hive, Mahout, etc. There are chapters on maintenance and monitoring. Lots of screen shots and command-line instructions.
I wish the book showed the latest developments in these areas, which are Cloudera Manager, HortonWorks Ambari, etc., which make it all ridiculously simple. However, when those managers fail or are not supported, you are still back on the command line, so this approach definitely has its place.
I especially liked the monitoring chapters, nagious, Ganglia and Ambari.