Well NG is the place for flash artists to show their skills so it'd be safe to assume that there are a plethora of tutorials if you can use your common sense. Seriously man, it's annoying when you ask these questions next time just search around for what you think might be the most likely place for it to be. I found this after clicking on the "Submit Content" and under "Flash" it says...
"Don't know Flash? You can find everything you need in thearea! "Newgrounds Flash
