I would recommend taking showing both of the attached cards to your guide and have them navigate for you for your first dinner out. Once you are comfortable in China and are a little more brave, you can venture out on your own.
This is the traditional card that you will find online. It has a very basic outline of what you can and cannot eat. I like how it says "my intestine would bleed", fear is a great motivator!
I also brought a printout of this note with me. I found it on someone's blog and I believe the translation is something like, "I will die a horrible death on your restaurant floor if you feed me gluten!"
Good luck. Have fun. Be adventurous...but not too much. You need to be well and able to navigate parenting your new child, travel, sightseeing and much more on your trip. I personally would rather go hungry and eat a Lara Bar back at the hotel room than risk being glutened and be sick for days.
I will do a follow-up post later on the food that I am planning to bring with for our next trip.
3/2/13 Edited to add this link: