Get yourself a "slate" or box call, or better yet, both. Make sure at least one will work in the rain.
Pattern your gun. You always aim wherever you have to, to put as many BB's as you can in the head/neck. They have kevlar feathers and you won't kill them any other way.
Scout alot. There is no substitute for scouting.
Don't call too much. A lot of guys, including the ones on TV, call too much.
Good luck and welcome to the madness that is turkey hunting.