Follow the other posters link. Also, note on your dining reservations that you have a person with this. There is a certain section that you can check boxes for allergies (peanut, tree nut, gluten, fish, shellfish, soy, etc). You would check the gluten box. Make sure then when you check-in for your meal that you note it again, and they'll have the chef come out and speak with you.
For CS and QS, just go up and ask to see a manager and they will help you, most have separate menus behind the counter for allergies. You just have to ask.