Python

• The Python Standard Library
• Beginner’s Guide to Python
• The Python Language Reference
• The Python Tutorial

JAVA

• Oracle – The Java Tutorials.
• Tutorials Point – Java Tutorial

Android

• How to create settings pages
• Material Design for Developers
• Fragmented Podcast
• Android Developers Backstage
• General:
  http://www.reddit.com/r/Android
  Android Niceties
  http://littlebigdetails.com/22
  http://android-developers.blogspot.com/30
  http://cyrilmottier.com/14
  http://stackoverflow.com/questions/tagged/android16
  http://android-developers.blogspot.com/30
  http://ecgreb.blogspot.com/2015/01/recommended-resources.html12
• Design:
  http://www.materialup.com/33
  http://www.androiddesignpatterns.com/32
  http://www.greenbot.com/article/2090128/11-killer-android-features-you-aren-t-using-but-should.html22
  http://www.androidcentral.com/how-enable-developer-settings-android-428