Take your chicken out of it's packaging. I like to rinse mine off in a slow stream of water (to avoid spraying chicken juice everywhere), but you don't have to do this. It's optional and some people advocate against it. The choice is yours.
Remove the neck and giblets from the center of the chicken if your chicken came with it. You can either discard them or make gravy with them.
Insert the skewer through the neck and butt of your chicken and attach the clamps that hold the chicken in place.
Using as much dried, ground rosemary as you like, rub it all over the chicken on both sides.
Place the chicken in the rotisserie and cook at 350 F. for about 1½ to 2 hours. The chicken is done when a meat thermometer inserted into the meaty part of the chicken leg reads at least 165 F. (I like to check with the thermometer in a few places just to make sure it's fully cooked everywhere.)
Remove the chicken from the rotisserie and place on a platter or flat work surface.
Remove the skewer and allow the bird to sit for about 10 minutes.
Carve as needed.
HINT: Save the carcass for making homemade chicken broth. If you can't do it immediacy or within the next 3 days, transfer the cooled chicken carcass to a zipper-top bag and freeze for up to 2 months.