Yes, it's VERY important to carefully measure the amout of oil you use. I usually only fry birds that are less than 15 lbs, usually I try to find them in the 12-13 lb range.
Make sure you remove the gravy and giblet bags before cooking!
Put bird in empty pot (on your turkey stand) and fill with water till it barely covers the bird. Remove the bird and mark where the water line is. I used a screwdriver or punch to mark the line on the inside of pot.
Empty water from pot and dry off bird completely.
Fill pot with oil (I usually use peanut or regular veggy oil) to your mark.
Heat oil to 325-350F and SLOWLY, VERY SLOWLY lower into oil. I cant stress enough the importance of going slow.
3 1/2 mins a pound, and add 5 mins (for oil to recover from cold bird)
Make sure you let the bird rest 20-30 mins before carving or shredding.
There are LOTS of good injection mixes out there. Inject before frying. I try to avoid puncturing the skin.
putting a rub on the outside sometimes leaves you with a ver blackend bird, I dont do it. Also try to not let the temp get over 350 at anytime.