Reddit mentions of Practical Ruby for System Administration (Expert's Voice in Open Source)

Here's what we do for our entry level people;

• Grab a machine off ebay or build your own and get vagrant up and running with a bunch of VMs from http://www.vagrantbox.es/ or use EC2 / OpenStack etc
  
• Sign up for Hosted chef (free for 5 nodes) https://getchef.opscode.com/signup
  
• Clone the OpsCode Git Repo and have a poke around
  
• Learn about Ruby and Git
  
• Learn what the Chef Recipes do http://docs.opscode.com/
  
• Start making your Vagrant / EC2 / OpenStack VMs actually do something by assigning Chef Roles and recipes
  
• Start monitoring your systems with Graphite, http://riemann.io/ and others
  
  Once you've done that sign up for DevOps weekly http://devopsweekly.com/
  
  Finally remember that DevOps is neither one thing or the other, learn a variety of programming languages, learn that traditional Ops silos don't always work and learn new ways of doing stuff (agile, infrastructure as code etc etc).

http://www.amazon.com/Practical-System-Administration-Experts-Source/dp/1590598210/ref=sr_1_1?ie=UTF8&qid=1347133830&sr=8-1&keywords=ruby+system+administration

)

Speaking of Ruby, I have appreciated Practical Ruby for System Administration when it comes to automating server stuff.

In your case, something like "Practical Ruby for System Administration" would work better.