Your refrigerator is your number one tool for food safety—keeping bacteria from multiplying. Check your refrigerator from time to time to make sure it is set to a nice cool temperature: somewhere between 32˚F and about 40˚F. Set your freezer to 0˚F or less.
Raw foods need to go into the refrigerator or freezer as soon as you get them home, especially considering their un-chilled travel time from the market to home. Cooked foods or leftovers need to chill as soon as possible after preparation: within a maximum of two hours or one hour during a hot summer. If you divide leftovers into small manageable containers, they will chill faster.
Inside the fridge, arrange stored food to promote cold air circulation; do not crowd.
Thawing food is a particularly important step. Never thaw on the counter at room temperature; bacteria will have feast! The safest place to thaw is the refrigerator, using a plate or bowl underneath the meat to catch juices. You can accelerate the process by thawing in the refrigerator in cold water, changing the water every half hour or so. You can also thaw in a microwave. Cook immediately after thawing.
Do not marinate meats at room temperature. Do it in the refrigerator, even if you need to move items to make space. Keep marinating juices from flowing onto other food items.