You can find specific information about what gluten is and how to go gluten-free from the famous gluten-free goddess Here and Here. That being said, there are lots of ways to approach the gluten-free diet. You can avoid all baked goods and breads (no fun!), or make them with alternative flours. You can buy pre-packaged gluten-free food and baking mixes (easy, but very expensive), or make them from scratch. So many companies are jumping on the gluten-free bandwagon (bisquick, betty crocker, etc.), but everything is healthier/tastes so much better if made from scratch.
If you are making a life-long commitment to a gluten-free diet, it is imperative (in my opinion) to buy a grain mill/grinder. It will save you so much money in the long run. I have heard that cheap coffee grinders also work, but have never tried them. I buy grains in bulk, and grind all of my own flour rather than paying a fortune for a small bag of specialty flour. My favorite flours for baking are sorghum, teff, millet, brown rice, tapioca, amaranth, and buckwheat. I grind a variety of flours on a weekly basis and store them in small, labeled pete containers in my fridge. I buy tapioca flour/starch at our local Asian market. It is incredibly cheap there. Tapioca is also a very un-allergenic food.
Everyone has their "signature" gluten-free flour mix. The secret to successful gluten-free baking is to use at least three different types of flour, and to make sure 1/3 of that flour mix is a starch. I use tapioca flour (also known as tapioca starch), but cornstarch and potato starch are commonly used in recipes. When looking at any gluten-free recipe, you can adapt it by taking the total amount of flour and coming up with your own flour mix. Sometimes I lower the amount of starch to 1/4. I would suggest playing around with different flour mixes until you find one you like. I change mine constantly depending on what's in my fridge. Bean flours and almond meal are also very popular in gluten-free baking. And xanthan gum is a must...I buy it in bulk, but it is available at walmart.
The internet is a fabulous resource for gluten-free recipes, but I would suggest investing in one book: "1,000 Gluten-free Recipes" by Carol Fenster. It is my cooking bible. She has many allergy friendly recipes and provides dairy substitution ideas for those on the gfcf diet. I adapt most of her recipes because I like to use more whole grains, but her recipes are fantastic.
Brown rice pasta is a staple in our house. I think it tastes much better than whole wheat pasta. Some brands are better than others. I stock up on brown rice penne at Trader Joe's, and Rizopia brand pasta at our local health food store. Trader Joe's is an excellent resource for gluten-free goods. I love their gluten-free gingersnaps. There is a big purple "G" next to all of the foods that are gluten-free, but you can also request a list of their gluten-free products.
Snacks ideas: brown rice cakes with organic strawberry jam, organic corn chips and hummus/salsa (best price at costco), fruit, veggies, kettle brand potato chips (gluten-free and non GMO), dried fruit (raisens, cranberries, etc.), popcorn/kettle corn, trail mix (choc chips, nuts/seeds, dried fruit), healthy homemade cookies/muffins, corn chex or other gluten-free dried cereal, etc.
Dining out: This is the hard part, especially if you are avoiding dairy too. When we are in a hurry we get protein-style (wrapped in lettuce) hamburgers and fries at In 'n Out Burger. The other places we eat out are Pei Wei's/PF Changs (awesome gf menu!), and Chipotle. Everything at Chipotle (aside from the flour tortillas/cheese/sour cream) is gluten and dairy free. Other Chains have gluten-free menus, just check their online menus for gluten-free options. One thing we buy a lot when we need a quick meal is the rotisserie chicken at Costco. It is both gluten and dairy-free. The one at Sams club has both wheat and dairy, so be careful and read labels.
Good Gluten-free Sites:
Simply Sugar and Gluten Free
Sure Foods Living
Whole Life Nutrition Kitchen
I have more links on my sidebar. Oh, and a breadmaker with a gluten-free cycle saves so much time. Read my post about mine here. I will try to edit this post as I remember more tips/tricks.