bigcountry,
Using a sight of some sort (pin, tip of arrow, mark on the riser, whatever)is definitely a good idea when working on your form or doing something like bareshaft tuning where consistent aiming is needed to see if the arrows are hitting together.
I normally recommend it to folks new to shooting trad equipment so that they can get there form down. Once you can consistently shoot the same way every time then you are ready to start learning how to aim. If you try to learn to aim before you set your form you are just wasting your time and getting frustrated.
Snakeeater