pluralsight has two very good electron courses.
https://app.pluralsight.com/library/courses/electron-fundamentals/table-of-contents
and I am finding this book. Cross platform desktop applications by Paul Jenson to be excellent.
https://www.amazon.com/Cross-Platform-Desktop-Applications-Using-Electron/dp/1617292842/ref=sr_1_1?ie=UTF8&qid=1506979098&sr=8-1&keywords=cross+platform+desktop+applications
pluralsight has two very good electron courses. https://app.pluralsight.com/library/courses/electron-fundamentals/table-of-contents
and I am finding this book. Cross platform desktop applications by Paul Jenson to be excellent. https://www.amazon.com/Cross-Platform-Desktop-Applications-Using-Electron/dp/1617292842/ref=sr_1_1?ie=UTF8&qid=1506979098&sr=8-1&keywords=cross+platform+desktop+applications