Gluten is a protein found in wheat products, barley, and rye. For someone avoiding gluten like it's the plague, I would suggest starting at your local grocery store. Something important to consider is the fact that the perimeter of the store is mainly populated by fresh produce, meats, poultry, fish, dairy, and eggs- which are for the most part naturally gluten-free. When you make your trips to the grocery store, you'll be buying most of your goods from these areas of the store. Try to avoid venturing out into the isles, unless you're looking to buy some rice, beans, quinoa, or gluten-free pastas and baking alternatives.
Once you've got that down, you'll already be well on your way to a consistently gluten-free diet. From here, you'll need to get into the habit of combing through product labels and lists of ingredients. Avoid anything that is made with wheat products, or if it says it came from a facility that processes wheat products. Many companies are starting to print "gluten-free" on their labels, which makes shopping a great deal easier. Never assume that a product is safe just because it is a naturally gluten-free product. Only recently did I come to find that some cheeses are washed in beer, so although there is nothing on the label that would give cause for concern, it will still fuck you up. Be sure to buy only name brands that are known to be gluten-free, such as boar's head.
Get creative in your kitchen. Find any recipe that interests you, and substitute the gluten-containing ingredients for gluten-free ones. Stock your pantry with gluten-free flour which can be used for thickening soups and sauces, breading for frying, or simply for making cookies.
Eating out: Avoid it. If you must go out to a restaurant, try to order a baked potato, which will always be gluten-free. If you happen to enjoy sushi anywhere near as much as I do, you can confidently order sashimi without risk of gluten contamination. Ask your server questions. If they have a grill, ask your server to find out what types of items are cooked on the grill. Avoid ordering food that is cooked on a grill where bread has been toasted or a sauce has been present. Never eat ANYTHING that has been cooked on a flat top. Avoid any fried foods that have shared oil with breaded foods. Lastly, avoid sauces. Many sauces contain wheat as a thickening agent. Always inform your server of your wheat sensitivity, and where applicable, request that fresh gloves be used when preparing your food.
Another cause for concern is the fact that a great deal of bath products contain gluten. This will not suffice to give you gluten-poisoning, however, it is likely that your skin will react poorly, and your hair may begin to fall out at an alarming rate. Check the labels, and don't use anything that contains "hydrolyzed wheat protein". You must also be aware that you can accidentally ingest gluten if you kiss someone who has recently eaten gluten or if they are drinking beer. Explain the importance of avoiding gluten to anyone eating at a table with you, and ask that they take care in keeping their food away from your plate. Do not share utensils or straws in order to avoid any cross-contamination.
I hope this covers most of the products that you should look to avoid. If you have any further questions, feel free to ask me in the comments, and I will answer as best as I can.
-Your Dear Elle