If “adb devices” lists your device but as “offline” chances are your path leads to an old version of adb (eg 1.0.29) which has problems with latest Android 4 devices.
Make sure “adb version” returns 1.0.31 or greater.
Starting with Android 4.2.2, you must confirm on your device that it is being attached to a trusted computer. It will work with adb version 1.0.31 and above.