Not much of a tutorial, but is still very much necessary to create any applications what so ever. Let's get started.
What is the ADT?
-The ADT Plug in allows for you to start creating Android based applications. ADT stands for Android Development Tools. It's basically crating a IDE inside your IDE.
Installing the ADT for Eclipse-Galileo
-1. Start Eclipse, then click Help > Install New Software
-2. In the available software dialog, click Add..
-3. In the Add Site dialog that appears, enter a name for the remote site (for example, "Android Plugin") in the "Name" field.
In the "Location" field, enter this URL:
Code:
https://dl-ssl.google.com/android/eclipse/
-4.Back in the Available Software view, you should now see "Developer Tools" added to the list. Select the checkbox next to Developer Tools, which will automatically select the nested tools Android DDMS and Android Development Tools. Click Next.
-5. In the resulting Install Details dialog, the Android DDMS and Android Development Tools features are listed. Click Next to read and accept the license agreement and install any dependencies, then click Finish.
-6. Restart Eclipse.
Configuring the ADT Plug-In
Once you've successfully downnloaded ADT as described above, the next step is to modify your ADT preferences in Eclipse to point to the Android SDK directory:
Select Window > Preferences... to open the Preferences panel (Mac OS X: Eclipse > Preferences).
Select Android from the left panel.
For the SDK Location in the main panel, click Browse... and locate your downloaded SDK directory.
Click Apply, then OK.
Done! If you haven't encountered any problems, then the installation is complete. Now read Adding Platforms and Other Components for instructions on how to complete the setup of your SDK environment.
And you have your ADT. If this wasen't clear, check the source here:
ADT Plugin for Eclipse | Android Developers