The IRS announced updates to the standard mileage rates for 2012 on Friday, December 9, 2011. IR-2011-116 keeps the business mileage rates at 55.5¢ per mile for business travel after 2011. Charitable mileage rates also remain unchanged from last year, at 14¢ per mile for service to a charitable organization. The rate for using a vehicle to get medical care or during a move decreases on January 1, 2012, however, from the July 1, 2011 amount of 23.5¢ to 23¢ per mile.
It is also helpful to keep detailed receipts and descriptions of your travel, as you also have the option of calculating the actual costs of vehicle usage, instead of the standard mileage rates.