When Mary Anne Fabian traveled to New York City after the World Trade Center attacks, taxes were the last thing on her mind. Fabian, 30, a guidance counselor from Liberty, South Carolina, and six fellow church members piled into a van, drove 15 hours to New York City, and spent the next five days cooking for rescue workers and distributing toys to kids who'd lost a parent in the disaster. "It was a wonderful yet humbling experience," says Fabian, who spent several hundred dollars for gas, food, and other expenses while on the trip.

Many charities say that volunteering and donations surged in the weeks after the attacks. And while you certainly don't do good works in order to get a tax break, you may be surprised by how much you're entitled to under IRS guidelines. Even though Fabian can't deduct the value of the time she gave to volunteering, she can deduct transportation costs to and from New York, as well as her meals and other expenses, such as phone calls.

One caveat: You can't deduct charitable donations if you don't itemize on your tax return — that is, if you file the E-Z form, rather than Form 1040. To see if the extra paperwork makes sense, tot up all the charitable things you did this past year. If your allowable donations, in combination with other deductible items (like state and local taxes and mortgage interest), are more than the standard deduction ($7,600 if married and filing jointly, $4,550 if single), you should itemize.

Here are the most common deductible donations:

Travel and meals. If you drive to and from volunteer work, you can deduct 14 cents a mile for the distance traveled, plus tolls and parking; if you travel by train, bus, or subway, you can deduct the cost of your fare. Sent by a charity on a do-gooding trip — say, to build houses for the needy in Appalachia? The cost of your meals and accommodations is deductible, provided you pay for them yourself. Even cell-phone calls made on the charity's behalf can be written off. Your statement serves as your receipt. Note: You can't deduct calls home just to say hi.

Clothing and household items. Goodwill, the Salvation Army, and other charities will give you a receipt for your donation, but valuing the items is your job.

High-end goods. Despite what you may hear from charities clamoring to get their hands on your junkmobile, you aren't always entitled to deduct the full blue-book value of your car. If it's in bad shape, it's worth less. (Go to Kelley Blue Book at www.kbb.com and click on "Trade In Value" for an estimate.) Also, the IRS requires that you get an independent appraisal of the value of any item or collection of items (say, a painting or a set of silver) worth more than $5,000. (You can find an appraiser through the American Society of Appraisers, www.appraisers.org.)

Cash and securities. When adding up your donations by cash, check, and credit card don't forget automatic donations taken out of your paycheck, such as those for United Way (your pay stubs serve as your receipts). If you donated stock that has appreciated since you bought it, you get a boost: Generally, if you've held the shares for a year or more, you can deduct their current market value rather than the amount you originally paid, and you won't owe capital-gains tax.

Other expenses. Did you buy gas masks for Trade Center rescue workers? Pay to copy 1,000 invitations to a charity event? Whip up 200 brownies for a church bake sale? Buy toys for a charity's party for disadvantaged kids? All are deductible, as long as you were never reimbursed for your purchases.

Before you claim any deduction, be sure to ask the charity if it is registered with the IRS as a 501c(3) tax-exempt organization (to double-check, go to www.irs.gov). Only expenses for donations to such organizations — or to churches, nonprofit hospitals, schools, and some government entities — qualify for deductions.
Finally, a word on documentation. If you've given less than $250 in cash or goods, you need a receipt, a canceled check, or an account statement that shows the amount donated and to whom. If you've given more than $250, you'll need a receipt from the charity that lists what you gave and states that you didn't receive goods or services in exchange for the donation. Once you've got those, you can rest easy — and wait for that refund check.