The IRS announced this week the new standard mileage rates for 2012. Most of the rates remained the same as the last six months of 2011. For regular business use, the rate is still 55.5 cents per mile (don't ask me where they came up with the half cent). For charitable purposes, the rate is 14 cents and for moving and medical expenses, it is 23 cents per mile.
You can use these rates to reimburse your employees for their business miles and or deduct businessuse of your personal vehicles on the farm.