By now you should know that all wheat is out. As well, most grains are also glutinous or risky because of cross-contamination, and will cause many to get those celiac disease symptoms. But what CAN you eat? Below is a partial list and guidelines.
Rice: While rice becomes a staple for many celiac disease sufferers, overdoing it can have it's consequences. Eating too much rice, or all of the same type of rice may in fact cause a similar allergy to arise. So along with the rice, vary your grains. Also be careful of white rice. Because white rice is less nutritious then a brown or red rice, much of the white rice is 'fortified' with vitamins and minerals. The problem with this is that it is common to apply the additives by first mixing them in to a filler, such as corn starch, which is very likely to have cross-contamination issues.
Quinoa: (This one is tricky to pronounce. It goes "keen-wah") Nutty in flavor, quinoa is gluten-free and has a fine texture and can be used as a flour and whole, as a substitute when any small pasta is called for in a recipe.
Millet: No, it's not just for the birds :) Millet can be used both ground as a flour or whole as a grain.
Buckwheat: Not wheat at all, this is a gluten-free grain.
Amaranth: My personal favorite. (makes awesome pancakes) Amaranth is one of those "Egyptian grains" along with teff, which is another of the gluten-free grains, although it is not so commonly found.
Like I mentioned, this is only a partial list of gluten-free grains available. Some will take some looking/asking around to find, but once you find a source and get used to using them for your regular cooking and baking, you will find it is not so bad. (remember the alternative!)