How should turkey be thawed?

There is no safer way to thaw a turkey than in a refrigerator, in its original packaging, atop a plate to capture potentially tainted drippings. Generally, thawing requires at least 24 hours for every five pounds of weight.
 
Submerging the turkey in cold tap water requires less time but greater attention to detail. The bird should be placed in leak-proof packaging, and water must be changed every 30 minutes to keep it cold. Expect thawing to occur at a rate of 30 minutes per pound. The turkey should be cooked immediately after thawing.
 
Depending on bird and oven size, defrosting it in the microwave is another option. Because microwaving may cause some areas to warm and begin to cook, the turkey should be cooked immediately after thawing by this method to retard bacterial growth.
 
Source(s):
USDA Fact Sheets "Turkey Basics: Safe Thawing"