Check out the following resources for further education on YANG and OpenConfig.
NETCONF and YANG Tutorial
The attached PDF called JUNOS-NETCONF-and-YANG-Tutorial.pdf covers the basics of NETCONF and YANG, and describes the current capabilities and future plans of Junos for supporting NETCONF and YANG.
No prior experience in YANG or NETCONF is required to understand the information. Once you read the attachment you should be comfortable with using Junos YANG.
Junos YANG User Guide
Refer to Junos documentation
YANG blog series on J-Net Community
A series of blogs on YANG and how Network Management entities should progress in the path to Network Innovation.
Extending SDN to the Management Plane
A talk by Anees Shaikh, Google Networks, Network Infrastructure team at Google.