Congratulations. I owned a Griz and they're a pretty fair shooting bow. I think you'll enjoy it a lot.

If you are shooting the bow daily, you can leave it strung. It won't hurt the bow one bit. If you will be leaving it idle for long periods of time, you may want to use a stringer and unstring the bow and hang it on the wall either horizontally with supports under the wedges of the riser or you can hang it virtically like Lilhunter does. Just make sure that you don't hang it where it will get direct sun through glass or heat from a fireplace or heating system. Like was said too, don't lock it up in the trunk of your car and leave it for any length of time. Even on a relatively mild day, the heat in a trunk can be detrimental to a wooden bow.

Have fun

Make them sharp and shoot them straight, or leave them home.