It is so easy to make chicken stock. Bone+water+boil. It's pretty much as simple as that. You can also put in beg like carrots, onions, celery and a bay leaf but these are optional and I didn't.
You can also make a 'brown stock' by putting the bones back in a hot oven and roasting them for 15-20 mins until they are brown. Don't let then burn. This does make a tastier stock but not necessary
After a roast pick off all the good meat for sandwiches or soup or a sauce, it takes a little while but worth it. Take the bones, skin, gristle and so on that is left and place it in a pan
Cover with water and boil for about an hour
Strain into a heatproof jug
You'll be left with stock but it will have some fat in it. Allow it to cool, cover and put it in the fridge for a few hours or over night.
Go through the bones again, if might seem tiresome but I got enough meat for a stir fry for one once I added plenty of veg and egg.
Once the stock has cooled a layer of solid fat will have formed on the surface. With a spoon scrap this off and throw away. You'll be left with stock the texture of jelly which can be frozen in bags
With a bit of patience and a few store cupboard ingredients a roast chicken can be stretched to make 3+ meals. From this I had the roast, a chicken broth, a stir fry and stock to make another dish
Find more recipes in my other guides or at www.theschoolofbalance.com and follow me on twitter @schoolbalance or The School of Balance on Facebook