Even if your tax situation isn't complicated, there's still documentation the Internal Revenue Service demands. But tax filing doesn't have to be an ordeal. And it can be less frustrating and less time-consuming if you have all the material at your fingertips.

By being prepared, you'll be ready to file your return at the earliest possible moment (the IRS usually starts accepting returns around mid-January). And the earlier you file, the sooner you'll get your refund.

Much of the paperwork you'll need to complete your Form 1040 will tell the IRS how much money you made so the agency can tax it. But there is also information that will help you trim your tax bill.

To help you organize your tax paperwork, here are some of the most common documents you'll need.

Filing by the (identification) numbers
The IRS tracks every taxpayer through a Social Security number. For those of you who file your own returns, this isn't a problem. If you drop all your data off at your accountant's office, make sure your Social Security number is in there, as well as your spouse's if you file jointly.

Do you have any dependents -- children, parents -- that you'll be claiming? Then you'll need those numbers, too. This includes everyone, even infants. If your kids don't have their numbers yet, contact the Social Security Administration immediately. A missing Social Security number for any person listed on your return could cost you.

The IRS could delay the processing of your return, slow down any refund or disallow a credit if you don't have the identification numbers to support it.

And don't forget the tax identification number of the person or business that takes care of the children while you're at work. You'll need it if you file for the child care credit. You should receive a statement from the care provider that includes the tax ID number, as well as the amount you paid, so you can claim the credit.

It is called an income tax
Since it's our income that the tax man wants a piece of, start thinking about the employment and income data you'll need to file.

By the end of January, every employee should get a Form W-2 from his boss showing how much was earned, how much was taxable and just what taxes were withheld. If you have more than one job, you should get a Form W-2 from each employer.

You say you're still waiting for your W-2? The IRS has a substitute form, Form 4852, you can use in its place. You'll need last year's final pay stub for data to enter on the alternate W-2. And even if you have your official tax form, check it against that last pay stub to make sure the W-2 data is correct.

If you're an independent contractor, the company you worked for should send you a Form 1099-MISC showing your gross earnings. You can view, but not download, Form 1099-MISC on the IRS Web site.

If you're self-employed, you have a bit more work to get organized. Track down all receipts and documentation for business-related expenses, from the mileage records you kept when using your car for business to the office equipment and supplies you bought to the utility bills you paid to keep the home office lights on.