Barney, Welcome.

A rule of thumb: 5 grains of arrow mass for every pound of draw weight. For example, if you're shooting 60 Pounds, you'll need a 300 grain arrow. Anything less can cause damage to your bow. Arrows are splined for a distinct draw weight (spline = an arrow's resistance to bending). It is not advised to shoot a light splined arrow through a heavier bow. I have seen people injuried (parts of arrows through hands, etc). Make sure your arrows matches your bow and vise versa.

Best of luck hunting!