When I was getting into ops 10 years ago the book "The Practice of System and Network Administration" by Thomas Limoncelli was a great overview (very high level

When I was getting into ops 10 years ago the book "The Practice of System and Network Administration" by Thomas Limoncelli was a great overview (very high level and not specific) that we all read. The Phoenix Project by Gene Kim is kind of a more modern uptake on it, but both can be read easily by people outside of the field and I doubt the first one will ever not be relevant. Both are more about establishing proper ops methodologies. If you're looking for something more low level, like a Programmers guide to sysadmin I can't think of anything off the top of my head.