IRS Offers Tips for Year-End Donations via IR-2008-138.
Individuals and businesses making contributions to charity should keep in mind several important tax law provisions that have taken effect in recent years.

Special Charitable Contributions for Certain IRA Owners-
An IRA owner, age 70 ½ or over, can directly transfer tax-free up to $100,000 per year to an eligible charitable organization. This option, created in 2006 and recently extended through 2009, is available to eligible IRA owners, regardless of whether they itemize their deductions. Distributions from employer-sponsored retirement plans, including SIMPLE IRAs and simplified employee pension (SEP) plans, are not eligible.
To qualify, the funds must be contributed directly by the IRA trustee to the eligible charity. Amounts so transferred are not taxable and no deduction is available for the amount given to the charity.
Not all charities are eligible. For example, donor-advised funds and supporting organizations are not eligible recipients.
Transferred amounts are counted in determining whether the owner has met the IRA’s required minimum distribution rules.
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Rules for Clothing and Household Items-
To be deductible, clothing and household items donated to charity must be in good used condition or better. A clothing or household item for which a taxpayer claims a deduction of over $500 does not have to be in good used condition or better if the taxpayer includes a qualified appraisal of the item with the return. Household items include furniture, furnishings, electronics, appliances, and linens.

Guidelines for Monetary Donations-
To deduct any charitable donation of money, regardless of amount, a taxpayer must have a bank record or a written communication from the charity showing the name of the charity and the date and amount of the contribution. Bank records include canceled checks, bank or credit union statements, and credit card statements. Bank or credit union statements should show the name of the charity, the date, and the amount paid. Credit card statements should show the name of the charity, the date, and the transaction posting date.
For payroll deductions, the taxpayer should retain a pay stub, a Form W-2 wage statement or other document furnished by the employer showing the total amount withheld for charity, along with the pledge card showing the name of the charity.
Also, a taxpayer obtain an acknowledgment from a charity for each deductible donation (either money or property) of $250 or more.

Contributions are deductible in the year made. Thus, donations charged to a credit card before the end of the year count for 2008. This is true even if the credit card bill isn’t paid until next year. Also, checks count for 2008 as long as they are mailed this year.
Check that the organization is qualified to receive a deduction.

For all donations of property, including clothing and household items, get from the charity, if possible, a receipt that includes the name of the charity, date of the contribution, and a reasonably-detailed description of the donated property. If a donation is left at a charity’s unattended drop site, keep a written record of the donation that includes this information, as well as the fair market value of the property at the time of the donation and the method used to determine that value.Additional rules apply for a contribution of $250 or more.

The deduction for a motor vehicle, boat or airplane donated to charity is usually limited to the gross proceeds from its sale. This rule applies if the claimed value of the vehicle is more than $500. Form 1098-C, or a similar statement, must be provided to the donor by the organization and attached to the donor’s tax return.

If the amount of a taxpayer’s deduction for all noncash contributions is over $500, a properly-completed Form 8283 must be submitted with the tax return.
Source-IRS website.