Confused about how to fill out a W-4 at work? Laura explains what it is and how to complete it correctly. Plus, you'll learn 7 reasons when you should adjust your withholding so your employer doesn’t take out too much or too little income tax from your paycheck. Get the Money Girl book at http://MoneyGirlBook.com. Read the full transcript at http://www.quickanddirtytips.com/node/9556