I would start
here. Click on "Smart Dashboard" under the topics section for additional links to smart dashboard tutorials.
There are a number of examples you can work though to get familiar.
A good exercise may be to try to create a dashboard for your 2013 robot, seeing as you are probably already familiar with how the code/controls/hardware work in that system.
A decent example of a custom widget (to do vision processing on the driver station laptop):
DaisyCV