Seconding this recommendation, and not just because I suspect YesThatTom2 is Mr. Limoncelli. It might look at first like it just goes over the basics (what a load balancer is, what config management is, etc.), but it covers a huge amount of material in very accessible terminology and does a lot to clear up best practices that might not be obvious at first. Just bought a copy for a new junior member of our team who is terrified by all this new stuff; I'm totally confident he'll be able to get through the book and feel much better about things.