How to install Android SDK in Eclipse on Mac

1. Go to the Top menu and chose Help / Install New Software... you will see something like this:

2. As you can see you have to enter Name for the plugin (e.g. Android plugin) and the URL where it is located https://dl-ssl.google.com/android/eclipse

3. Press OK. (If you will do it for the first time you will be able to click OK).

4. Then just follow the instruction of plugin installation process.

Check this link for more details http://www.talkandroid.com/guides/developer/android-sdk-install-guide/