And your two best resources are going to be the dev site
developer.google.com, and google. (Other good resources are stack
overflow and #android-dev on freenode). There are 4 things you need to
know about android:
1. Activities - What you see on the screen and interact with.
2. Services - Things your app does in the background, often in another
thread.
3. Intents - The glue that sticks activities/services together, even
from different apps
4. Content Providers - Anything that provides content, often backed up
with an sqlite database.
Java and C# are very similar so you shouldn't have nay problems there.
Just use auto-complete to bail you out (ctr+space), oh, and you can't
use lambda notation like you can in c#, but java does allow for
anonymous inner classes, so you can have functors, which act like lambda
notation, but have a bunch of crap on the outside, not too big of a deal
though as auto-complete will type the crap out for you.
Finally, make sure to learn about the lifecycle of each component, and
possibly follow the notepad tutorial (again in the documentation).
~Leif Andersen