I was purchasing boxed coconut milk from the grocery store for smoothies and oatmeal, but when I looked at the ingredient list, I was a bit mortified. I noticed that it wasn't even coconut milk, but rather a coconut beverage. That was the end of that! I now make my own and it's very easy.
8 oz (2 1/2 cups) unsweetened shredded coconut
4 cups hot (not boiling) water
Put these ingredients into a blender. Start off on the lowest blender setting and slowly move up to high. Blend for about a minute and then let the mixture sit until it cools a bit. Pour the coconut mixture into a nut milk bag (or fine mesh sieve or colander) over a bowl. Squeeze out the milk out and reserve the coconut pulp. I recommend refrigerating the milk before using it in a smoothie. :)
Drying the left over coconut pulp in a food dehydrator makes a reasonable coconut flour.
I use coconut cream in a lot of my cooking over the winter, curried chicken being one of my favorite cold weather dishes. I usually purchase canned coconut cream for that because of it's nice and creamy consistency.
Click here for an interesting article entitled Why Coconut Milk May Not Be Your Friend, by Chris Kresser.