adb logcat. That's where all your System.out.println()s will show up as well as stack dumps of your fatal exceptions.
Not that I ever get fatal exceptions, that is.
Second protip: The ID being assigned in the layout MUST be the android namespace id (
android:id), NOT the XML
id. Doing the latter will cause your calls to findViewById() to return null. However, the ID will be placed into the R file regardless. Which can be confusing.