Here we go, yet another Android coding blog. Let's get this one item out of the way up front.
If you are going to write apps for Android (and you are right? otherwise why the heck are you reading this?) you are giving yourself a huge handicap by not having the Android source code on your Dev machine(s).
So if you get nothing else out of this blog, I implore you, please, take the time to pull the source code and learn the layout. Learn the coding styles. Read the comments. I honestly believe that you should not be hired as an Android programmer unless you have pulled the code at least once.