I was just playing with this last night. Really nice (and seemingly accurate) archery calculator
http://backcountrybowhunting.com/articles/calc/
I have only been shooting for a year but from what i can gather your arrow weight should be geared towards speed if you want to only shoot targets and if your going to hunt maybe go with a bit heavier arrow to retain the energy upon impact. BUT always use the same arrows you practice with otherwise you will not know where they are going to hit
Also get arrows Spined for your draw weight ( I shoot Xweave 300 at 70 lbs and my buddy shoots Xweave 200 at 60lbs ) If they are over-spined you wont get the speed or flex needed on release and if they are under-spined they can flex to much and break. I have heard stories of broken arrows going through the bow hand's wrist due to damage and to light of arrows