Depends on how deeply you want to get involved. There are aluminum arrow charts that have been around for decades that will get you in the ballpark. Or, you can get into arrow tuning. There is a wonderful 4 disk series called, "Masters of the Bare Bow," which explores all aspects of traditional bow shooting. One of the sections, on disk 2 I believe, is on bare shaft arrow tuning by Ken Beck, the (semi) retired president of Black Widow Bows. I learned from Ken at one of the clinics he puts on with Fred Asbell at the Black Widow factory in Springfield, MO, and have used his method ever since.
I should say, however, that trying to tune arrows before you develop good form is putting the cart before the horse. It's not so much that you can't tune arrows before you develop good form, as that the tuning will change as your form changes, so what might be a well tuned arrow at one point in your archery development might not be what you want later on. So it might be best to start with the charts, and not fix up too many arrows at a time until you have a better idea of what you want.
Even so, the MBB series of disks is a wonderful introduction to traditional archery and will help you make choices about many different things.