So how exactly do you make the switch from eating "normal" food to eating GF/CF? My best advice? Go slowly! When we were first starting this adventure I focused on showing my kids that they will still have great "treats" to eat, because of course that is what kids worry the most about. I played around with the flours until I found one that not only worked taste wise, but also worked for our budget.
I read a ton of blogs to get ideas. There is so much information on the web, use it!
I would go to the store and buy one of each brand of something, for instance, non-dairy milk. There are so many varieties out there, which can be overwhelming. The great part is, though, that lots of variety means lots of choices! My son likes Rice milk while I love Almond, so we buy both now. Take notes about which brands you liked/didn't like. I made the mistake of not keeping track at first and re-bought items we didn't like. If you accidentally do that, remember that you can use any kind of non-dairy milk in your cooking and you can't tell the difference.
I looked for products that we were already eating that are already gluten free, such as bacon, lunch meat (make sure you read the package!), hot dogs (again, check the package as many contain Casein), fruits, veggies, meat. Many foods that are "whole foods" naturally do not contain G/C.
Start cooking. Being GF/CF means cooking from scratch a lot unless you are blessed with an unlimited income, which I am not. I happen to think that home-made GF/CF items taste better simply for the fact that GF/CF items don't store well. That is why a lot of the packaged foods tend to be dry and break easily.
Be prepared for flops. I not only had to contend with flops, I also have a son that is extremely picky with his eating. Sometimes GF/CF stuff doesn't work out the first time you try it. Don't be afraid to try again! In the beginning I was using some of the bean flours and couldn't figure out what in the world the "weird" flavor was in the food. Well, it was beans! That is why I stay away from GF "mixes" such as Bob's red mill, many of them contain bean flour. Be prepared to waste some money in the beginning, there is a definite learning process here that you have to get through.
Be willing to give up foods that you can't mimic. My son still won't eat a non-dairy milk with a bowl of cereal, so he doesn't eat cereal anymore. I haven't found a GF spaghetti noodle that I like, so I don't eat spaghetti anymore. It took a long time to make a GF/CF bread that we liked, so for a while, we didn't eat bread (or we paid a crazy amount for a pre-made loaf at the store). I am thrilled that my son now likes my home-made bread better than Udi's!
Don't give up. Your taste buds WILL change. We recently tried my son on a milk challenge and it was so hard because he couldn't stand the taste of cows milk! This from a child who used to drink almost a half-gallon a day!