I'm not a sysadmin or servers guy, but these days I happen to manage most of the devops and so getting servers and machines set up is my responsibility.
Ansible docs are not great for getting started, and I pretty much just learned by skimming through some Playbook, and figuring it out their — often intuitive — purpose.
After a few hours I got to a close to getting my machines set up with most of my Django stack: Nginx, Gunicorn, Redis, supervisor, celery, etc. The only thing that I couldn't properly set up was PostgreSQL. And here is something that most of these automation tools lack: debugging. When my postgres roles was failing, I had no clue how to even start debugging it, so after an hour or so, I just stepped back and went in to set it up manually.
I feel some of these tools need to be more friendly with devops that don't have quite the same knowledge and experience than the target audience of sysadmins and ops people. That said, I learned a ton starting to use Ansible and automated a big chunk of the process.