This is a large subject to cover but I need to make a start. For me DevOps so about having people work together to make sure development and operations are talking and working together to deliver automated releases. The key to success with DevOps is people, everyone needs to be onboard, including people working in Change Management and Service Delivery.

So, some useful resources:
DevOps Learning Guide for Agile, Git, & CI
DevOps Defined | HashiCorp
DevOps Topologies