Android Devices Programming Start Up

Hello All

Android devices is still booming. Every 3 months, many vendor release their handset based on this free mobile OS.
For us who have a passion for writing a code, program or making an application, Android is a promising system , it's free and open. We can easily made ours app without getting headache like other development language.
The question is, what Android is about ? How to making an environment that ready for Android programming ? What language do we have to know as a first step for writing Android based code ? Do this environment has a IDE ?

Android is a free Open Source Mobile platform that run in multiple device, named like Cell Phone, Smart Phone, Tablet, and now its a fundamental system for Google's Chrome OS for Netbook.
We can make an environment on our PC or laptop for this system, using this link we can learn how to set up their environment.
Android was a Java code all about. The tools that ready to use can be download from this link.
A nice simple set of many sample code can be download from this link.
For a simple and best environment , i prefer using Eclipse IDE .

Hope this articles will help U guys...