Android Tutorial: Getting Started
After deciding to develop for Android rather than the iPhone, it's time to get started. Here are the necessary steps for newbies...
Step #1 - Download and install the Android SDK
Pretty straightforward. Go to http://developer.android.com/sdk/index.html, and download and install. The only "special" instruction is, for Windows users, right-click on My Computer, and select Properties. Under the Advanced tab, hit the Environment Variables button, and in the dialog that comes up, double-click on Path (under System Variables). Add the full path to the tools/ directory to the path. then Restart your machine.
Step #2 - Download and install Eclipse
Again, straightforward (isn't that nice?). Go to http://www.eclipse.org/downloads/, and download and install the language of your choice. Especially for GUI development, I'm a Java fan, myself.
Step #3 - Download and install the ADT plugin
Finally, you'll need the ADT (Android Development Tools) plugin for Eclipse. Download and install it using the instructions at http://developer.android.com/sdk/eclipse-adt.html. There's more steps involved with this installation, but nothing will work without it, so be diligent!
At this point, you're done and should be all good to go. I highly recommend this wonderful tutorial by Lars Vogel to step you through the process of creating your first fully functional Android app (code included). And after that, the sky's the limit.