Take a whole raw chicken and plop it in a 4.5qt or 5qt crockpot (or 2 smaller chickens in a 7qt crockpot), add 1/4 cup water just to get some steam going, cook on high for an hour, then turn it down to low and leave like that until the chicken(s) is(are) thoroughly cooked (could be anywhere from 3-6 hours, depending on the size of the chicken, whether you did one or two, and how big it is/they are).
Remove chickens, allow to cool until they can be handled without scorching yourself.
Remove all meat, store for a later use of your choice. Put everything else back in the pot, fill with water, add veggies for extra flavor if you like (I usually don't), cook on low for 24 hours, giving it a little stir when you feel like it (can go overnight without stirring). Strain stock, refrigerate until cold (will be gelatinous, as most good stocks are when cold, due to collagen from the joints), remove the fat that rose to the top and store in the freezer in a Ziploc baggie or a small container (can be used to make a roux later for the best gravy ever).
Freeze until ready to use - some people I know freeze stock in ice cube trays for when they only need a little, but I generally don't go smaller than a pint because I usually don't need less than that.
