How do you turn on developer options (debug, adb, etc) for the Samsung Galaxy S4?
Build number
optionNow you'll have developer options under the System heading, from where you can enable USB Debugging etc.
Also make sure you're running the latest tools on your computer, as 4.2.2 onwards you have to verify the RSA key for ADB. This is not available unless you are running the latest version of ADT, and your device will appear offline when connected if you're using an older version.
References: Android Central, Haptic Antics