The difference between stock and broth are very simple. Broth is made using the meat of the chicken, while stock is made using the bones. As for veal and chicken stock, there is not only a big difference in taste, but color also. That is because when making a veal stock the bones are browned before being used, so that you get that nice flavor, which also gives veal stock its darker color.
There are also fish stock and vegetable stock. I mean really you can make a stock out of anything, Rabbit stock, shrimp stock, the list could go on forever.
When making a simple chicken stock add the bones, cold water, and mirepoix. Mirepoix is just a fancy french word for a mixture of carrots, celeray, and onions. The most common ratio for mirepoix in a stock is 50% onions, 25% carrots, and 25% celeary. Along with the mirepoix and bones, a sachet is added. A sachet usally consists of bay leaf, whole pepper corn, cloves, garlic, and parsley stems. They are tied together in a cheese cloth and added to the stock. The stock is then simmered, strained, and then done.
I hope that answered a few of your questions. If you have any more questions I will be glad to answer them.