Soup Stock

Bring the heat up slowly to a simmer. Boiling clouds the stock.

If you like more colour, try roasting the bones in the oven first until they brown up some.  It'll transfer the colour and make for a richer stock.  I tend to throw some onions and carrots in for the roasting as well.

I believe MaryB is also correct about the boiling.  I am perhaps lazy, but I'll roast the bones, add water to the roaster pan along with the other ingredients, and leave it in the oven to simmer overnight.  I make a lot (read: A LOT) of stocks, and this method works for me the most consistantly.

There are several great existing threads on making stock.  If you do a search for them I'm sure you'll find some awesome suggestions, guidelines, and ideas.  I did

As Mary said, bring the water to a simmer, never boil.  Second, add the vegetables towards the end of the process.  It doesn't take as much time for the vegetables to give up their flavor as it does for the bones/meat.  Cook vegetables too long and some will start to disintegrate and add some degree of cloudiness to the stock.  Finally, be sure that the bones have not been broken or cut as that will leach blood and other debris into the liquid.  And, of course, watch the stock carefully, certainly in the early stages, and carefully and thoroughly skim off any impurities.  Be sure your vegetables are clean as well.  Peel and rinse vegetables whenever applicable, such as with carrots.  Finally, for an added nicety, quickly blanch and rinse the bones and meat before adding them to the cold water in the stock pot.  If you blanch in the same pot that you'll be making the stock, clean and rinse the pot before adding the fresh water.

Simmer, Degrease

strain and let it rest in a fridge, any sediment should settle then skim again if necessary, ladle out the stock without any sediment

Here is one I learne from one of my chinese chef associates .Amazing try it    
Assemble
2 cups water
1 1/2 teaspoons Monosodium Glutimate
About 1 to 2 teaspoons salt to taste
few drops yellow food color
1 onion skin

some green onion and spinach for garnish

Method
  Boil water add salt, msg,color and onion skin let sit 43 or 4 minutes   top with shredded spoinach and scallion. If you want you can add beaten egg thru colander for egg drop.

CHICKEN SOUP ???????????? MAYBE

We just had a similar discussion in my 'Clearly better tasting' thread.

As others have said, try NOT to boil the stock.  Think more of steeping than stewing.  And I usually let the bones go for an hour or two before putting the veggies in.  As Schmoozer said, veggies don't take that long to get all used up, maybe an hour.

A good, homemade stock is always nice to have on hand.  I usually have some sort of stock in the freezer and fridge.  I will confess, however, that I have been suffering from a cold and the other day I did buy a canned beef broth instead of making my own.  Oh well.

mjb.

Yeah i argree . I heard that some of the cook told that overcook vegetable deteriorates the flavor ,  adding the vegetables one hour before the stock is done cooking.will need to roast the vegetables separately while the stock is simmering and then add them during the last hour of cooking.