NEW YORK (CNN/Money) – If you've perfected the art of procrastination, you know very well what will occupy your time in the hours before 11:59 p.m. this evening: the 11th-hour tax shuffle.

That's the deadline for paying what remains of your fair share to Uncle Sam and to your state and local governments.

Money Helps: Last minute tax crunch • Party time at the post office • Most overlooked deductions • Biggest deduction myths • Coping with Schedule D • 5 ways to avoid an audit • Tax scams to avoid • If you owe...

You're hardly alone in your quest to beat the clock. Last year, nearly 27 percent of the total returns the IRS received were filed in the two weeks prior to the April 15 deadline.

As you race to get everything done, you might want to use this checklist to make sure you don't forget critical elements that can either delay the processing of your return or cause you to forfeit some breaks (and possibly a refund) to which you're entitled.

Get the right stuff. If you're going the paper route, it's hard to file your taxes if you don't have the right forms or the right information about how to fill out those forms.

For your federal return, you can print out any form or publication you need from the IRS Web site.

CNNfn's Gerri Willis shares five tips on how e-filing can work for you. Play video (Real or Windows Media)

For state forms, your state government's Department of Revenue Web site is likely to have them online. (The Federation of Tax Administrators provides a state-by-state listing of such sites. To view it, click here.)

If you wish you had a tax preparation software program but didn't want to incur the cost, you may be able to use one of a number of free online tax prep and e-filing programs that were set up by a group of 17 tax preparation services in a partnership agreement with the IRS.

Each service has its own eligibility requirements – so you'll first have to see if you qualify for any of them.

There are just hours left to get your taxes to Uncle Sam. If you just can't get it done in time - what will it cost you? Play video (Real or Windows Media)

Ask the right questions. It's also hard to fill out your return properly if you have lingering questions – however basic -- about a tax issue.

You may find some of the answers you need by checking out the IRS' 1040 Central.

Don't shortchange yourself. In your haste to be done with your taxes, you may overlook a deduction or credit that you're eligible to take.

Even if you don't itemize, there are plenty of tax breaks to which you may be entitled. For a look at some of the most overlooked ones, click here.

On the other hand, there are plenty of false notions about what's deductible and what's not. For a look at the some of the biggest deduction myths, click here.

Steer clear of common mistakes. Scads of filers make simple math errors every year. So be sure to double-check your math.

This year, however, the No. 1 mistake the IRS has noticed is that tax filers are failing to report or are misreporting the amount they received for their 2003 advanced child tax credit. The cap rose $400 (from $600 to $1,000 per child) and many parents received checks last summer as an advance on that credit.

CNNfn's Valerie Morris shares tips on how to avoid the most common tax mistakes when filing your taxes. Play video (Real or Windows Media)

If you've forgotten how much you got, the IRS provides a quick online questionnaire you can fill out to confirm exactly how much you received.

For investors, this is the year of the qualified dividend and lower capital gain rates. You know what that means, of course: A more complex Schedule D. For help navigating your way through it, click here.

Make it perfect. Here's the perennial cross-your-T's and dot-your-I's suggestion. Be sure to include your correct Social Security number and don't forget to sign your return.

Make it later. If all this seems unmanageable by the tax deadline this evening, give yourself a break and file for an extension. It's easy enough to do. Just fill out IRS Form 4868.

YOUR E-MAIL ALERTS Taxation Internal Revenue Service (IRS) or Create your own Manage alerts | What is this?

You can efile it by computer or by phone or you can mail the form in. Just make sure you do so by 11:59 p.m. tonight. Otherwise, you may be subject to late-filing penalties.

If you think you're going to owe money this year, you might want to include a check, too. If you don't, then you may be hit with late-payment penalties.

Short on cash to meet your bill? Click here to see how you might handle the debt.