Hi Tom,
Last year, I started to learn Android by checking out Google's
Android Developer's Guide. I've done
alot of reading at this site and have learned much about Android from this material.
The result of my journey into this documentation was the creation of a pair of articles for my website:
Android Activity Lifecycle and
Hello, Android!
Yesterday, I encountered a very interesting video of Google's Dan Morrill discussing Android technical features (such as activities, apks, content providers, services, intents, and so on) and why things are the way they are. Dan's
Inside the Android Application Framework video is from the 2008 Google I/O conference. I've watched this video and much (if not all) of it appears to be still relevant. I recommend that you check it out.
I am currently working on a book on Android development for Apress. However, it will take a few months before this book project is complete.
All the best.
Jeff