inject, don't brine. I use a mixture of williams creole butter injection mix with a bottle of Evangeline or Louisiana hot sauce mixed in with a bottle each of McCormick liquid onion and liquid garlic. Good stuff.
Tony is right. 3-1/2 minutes per pound is a good way to go, and it is very important to fry smaller turkeys only. They turn out much better. I like to keep mine around the 10lb and under mark.