Start by thawing and cleaning turkey, if brining do not use a self basting turkey.
To butterfly, cut out backbone, turn over, placing cuts where needed to allow turkey to lay "flat". You will need to crack the breastbone and disconnect the wing and leg joints. Do this by breaking the joint in the cartilage, I removed my wings completely and used them along with the back bone for stock, you may keep them in place.
Brining- in large container place 1 c salt and 1-2 gallons of water, enough to cover turkey. Optional- add a large handful of fresh herbs, thyme, rosemary, oregano, sage etc. Keep covered and in refrigerator 6 hours to overnight. Remove, discard brine and herbs, pat turkey dry and place on rack above a large pan, big enough to catch drippings.
While cooking you may baste with a marinade or juices but it is not necessary. Cook 2-4 hours, or until meat thermometer reads done.
Butterflying decreases cook time be sure not to overcook.
Let rest 15 min and carve.