Ansible - an absolute basic overview
Despite being several years old, my YouTube video giving an introduction to Ansible seems to be rather popular, and it is still relevant despite the numerous version updates that Ansible has seen in the meantime.
There is one key change in the way Ansible playbooks are normally written which has changed over the years, partly to make them conform more to YAML conventions.
A line like
apt: update_cache=yes cache_valid_time=36000
would now more commonly be written as:
apt:
update_cache: yes
cache_valid_time: 36000
So you may notice a few changes in recent documentation, but this should still be a good introduction to the topic.