I once thought I just have to plug the device in, install all the driver and when it appeared in ADT’s device window I can just start debugging; but sadly this is not the case. Here’s a very informative guide on how to do so by Google.
Because I was too lazy to read that, I can start the program but it will not hit any breakpoint I set. I missed the first point in the guide above: I have to set debug=”true” in the application’s manifest!
<application android:icon="@drawable/icon" android:label="@string/app_name" android:debuggable="true">