To make chicken stock, here's what you do:
Take the carcass and pick off any of the edible meat that is left. Store that in the fridge til you are ready to make soup.
Put the carcass in a large pot and fill the pot with water until the chicken is nearly covered in the water (it can poke above the water a little). Add 1-2 celery stalks, 1/2-1 onion chopped, some carrots. You don't need to worry about cutting the veggies up in little bits because you will be discarding most of it at the end anyway.
Boil the chicken with the veggies for 2-4 hours on med-low heat covered. Whatever you prefer. Then strain everything keeping only the liquid. Add salt to taste and you're done!
To make a soup out of it add whatever you like. Chopped carrots, celery, onion, rice, etc.
Here's how I make it:
1/2 cup wild rice
1/2 cup basmati rice (white or brown)
leftover chicken pieces, chopped
1 cup kale or spinach, chopped
1/2 cup carrots, chopped
1-2 stalks celery, chopped
1/2-1 cup onion, diced
thyme to taste
pepper and salt to taste
I usually use all my stock for this recipe which is probably 1/2 gallon of water, maybe more. I put the wild rice in the stock first and boil it for 20 minutes (my wild rice usually takes 40 minutes to cook). Then I add the other rice and boil for another 10 minutes. Then add all the other ingredients, except the chicken pieces and boil another 10 minutes until the rice is cooked. Add the chicken and more thyme, salt and pepper if necessary. You've got yourself a hearty chicken soup. One thing to note is the rice will absorb ALOT of the liquid and especially if you don't eat it all in one day the rice gets all puffed up. But it still tastes good!