Learn by example. Check out sample SharePoint Framework client-side web parts connected to the Office Graph published by SharePoint Patterns and Practices.
Here are the presentation slides that I used in my recent presentation about building solutions on the SharePoint Framework at the recent SPS Brussels.
Recently Microsoft released the SharePoint Framework. Here is how you can try it without installing it, or any of its prerequisites, on your machine.
At the recent TechDays NL 2016 I had the pleasure of presenting three sessions about developing on the Office platform. Here are the slides I used.
Recently Microsoft announced the public CDN capability on Office 365. See how to use it to host your SharePoint Framework client-side web parts.