True what fitch said. For beginer big game hunters alot of people recommend shoulder shots. Any deer shot in the shoulder will drop instantly, it's breaks the front legs and goes through the lungs/heart area. They may get up and stumble a few yards after that, but they will not make the yardage that a lung or hear shot deer can make. Alot of times a deer won't even flinch when shot right thru the lungs, and they may not bleed alot or leave sign on the ground, but if you shoot their legs out from under them they're garunteed to fall, and until you get alot of hunting, and with your gun, I'd recommend shoulder shots.
And yes, 100gr. are good for deer, that's what I use in my .243. What model are you shooting? Good luck, Bad.