I'm working on Ansible for DevOps[1]. You can download a preview, which has a couple good chapters on setup and initial usage. Even for managing one server, a configuration management tool is a major help; I've started using Ansible to manage my Mac workstation as well[2] (so I can keep my two Macs in pretty much perfect sync).
I only assume the reader has basic command-line familiarity, but I try to make the writing approachable for both newer admins and veterans.
I hope to have the first draft complete by summer. I'm planning on pushing out a new chapter every couple weeks, and already have notes and material for four more chapters... Just need to keep writing.
Right now I'm working on a chapter on security, and another on Roles, and will probably publish an updated version next week.
I'm also working on getting one or two really good technical editors, as right now I'm basically doing my own editing as I go, one chapter at a time. Once I feel comfortable with where the book is, I'll be publishing on Amazon so people can get a hard copy.
I'm publishing as I go on LeanPub; I've written a little about the process so far on Server Check.in[1]. I'll probably work on getting the book on Amazon/Kindle before it's in its '1.0' state, but LeanPub will always have the latest version of the book (including after the '1.0' release).
I only assume the reader has basic command-line familiarity, but I try to make the writing approachable for both newer admins and veterans.
[1] https://leanpub.com/ansible-for-devops
[2] https://github.com/geerlingguy/mac-dev-playbook