Android 3.0 SDK

The Android 3.0 platform is available as a downloadable component for the Android SDK.

Install the Android SDK in Mac OS (MacBook Air)

scottshu$ cd /Users/scottshu/android-sdk-mac_x86
scottshu$ tools/android update sdk

Install the ADT (Android Developments Tools) Plugin for Eclipse.
ADT plugin for Eclipse

Add Android platforms and other components to your SDK.






Reference:
http://developer.android.com/sdk/installing.html