Here you are a list of useful links listed per technology:
JavaScript:
– https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide
– http://www.w3schools.com/js/default.asp
– http://www.tutorialspoint.com//javascript/index.htm
– http://javascript.info/
Ionic Framework:
– http://ionicframework.com/getting-started/
– http://ionicframework.com/docs/
– http://mcgivery.com/100-ionic-framework-resources/