Android Reference

SDK


http://developer.android.com/sdk/index.html

Architecture


http://developer.android.com/guide/basics/what-is-android.html

User Interface


http://mobiforge.com/designing/story/understanding-user-interface-android-part-1-layouts

Developement Tutorial


http://www.vogella.de/articles/Android/article.html

News


http://www.helloandroid.com/tutorials/newsdroid-rss-reader