Starting out on Android development

I have an idea for an Android app that I want to start working on. Where is a good place to start?

In the long run I know I'll need to know how to do the following:
1) interact with the GPS to get current location
2) synch to a database somewhere on the interwebs - odds will be that the database will be behind a firewall, so I'll be interacting with it via web method calls (ala PHP).
3) allow users to signup/in, create profiles
4) allow users to take and submit photos

I don't want to go too nuts with the features and if possible support as low as ICS Android.

I am starting with the Android Developers site, but if there are any other decent resources out there that might help me, that would be terrif.

-tg