Many recipes advise you to skim the stock of fat, I prefer to leave the fat to protect the contents of the stock while storing in the fridge, plus the fat adds flavor. If you prefer, you can of course skim your stock.
Many recipes will advise to add salt and pepper, I do not. I prefer to leave the salt and pepper out as I want the flexibility of adding my stock to sauces, gravies and soups which may have already reached its salty, seasoned peak. You can always add salt and pepper as desired once you have added your stock to a recipe.