I go by this:
Defrosting
First of all, if you've bought a frozen turkey, you'll need to defrost it. This works best if you plan ahead—it may be tempting to leave the turkey out on the counter overnight, but this is exactly what the invasive bacteria in your kitchen are hoping you'll do. Not a good idea. Instead, use one of these methods:
Defrost in the refrigerator: According to the U.S.D.A., this is the safest choice. There's no chance of harmful bacteria growing, and a bird defrosted in the fridge can be safely re-frozen if plans change.
Pros: Cons:
There's practically no effort involved: Just leave the turkey in its original wrapper and place it in a shallow pan to catch any leaks. This method is time-consuming, and the turkey can hog valuable fridge space during a hectic season. Allow 24 hours for every four to five pounds. (A 13- to 16-pound turkey would take three days.)
Defrost in a cold-water bath: If you're short on time or fridge space, this is your best option. You'll only need about 30 minutes per pound of turkey, so a 13- to 16-pound bird will be ready to go in six to eight hours.
Pros: Cons:
Much faster, and leaves your fridge free for other holiday preparations. This method is labor-intensive. First, make sure the wrapper is water tight, with no tears or thin spots in the plastic. (You don't want the water to soak into the bird itself, and you don't want any bacteria to leak out of the bird and into the water.) Submerge the turkey in cold water in a basin or sink, and check with a thermometer to be sure the water is 40°F or colder. As the bird thaws, drain and replace the water every 30 minutes, always checking to be sure it remains below 40°F. (If you live in a cold climate, placing the basin outside will help keep it cool.) When you're done, be sure to scrub the sink or basin thoroughly to remove any bacteria.
Read More
http://www.epicurious.com/articlesguides/howtocook/primers/turkey_shoppingandprep#ixzz2Cvpcy1en