When starting to develop applications for a new platform for me a good introduction to the topics are important. Often I try to find a good book to read and some good examples to analyse.
With Android examples are no problem. The Android SDK i shipped with lots of examples covering many of Android functionalities and the Internet is filled with samples, howto's and code samples
When I think about how development was back in the 80ties without Internet search engines life has become a lot easier for developers – and writers of manuals :-)
I have been browsing through a couple of Android books in the last year. The one that has taken most of my time is Professional Android 2 by Reto Meier from Wrox.
An other of my favorites are Pro Android 2 from Apress by Sayed Hashimi, Satya Komatineni & Dave MacLean