While taxes affect you as soon as you're born, most of us don't even start thinking about them until the momentous day when we get our first paycheck. That's when we come to the distressing realization that we don't get to take home all the money we've worked so hard for. Uncle Sam is getting a piece of it, and sometimes it seems like it's a very big chunk of change.

This is because of something called payroll withholding, which is basically pay-as-you-earn taxation. While the IRS trusts us to file our taxes accurately and on time, the U.S. Treasury finds it easier to pay for federal programs if it gets some of the money before April each year. So taxes are taken out of your wages before you receive the money, deposited in an IRS account and credited to you when you file your return.

You can't get around withholding, but you do have some control over the amount. The easiest way to manage how much tax is withheld is through the information you provide on one of the first forms your boss gave you: the [PDF] 

2010 Form W-4.