Start in your pantry and toss packages you haven't used in the last six months to a year. Check the use-by date: if it's past, call the 800 number to check how long your product is safe.
Keep spices, olive and nut oil away from heat and light to prevent spoilage.
In the freezer, toss out unlabeled and freezer-burned foods, and make sure the deep freeze isn't packed nor empty -- circulating air is needed for proper temperature, which should be zero.
Check the fridge for past-due dates as well and remember the F.I.F.O. rule: First In, First Out -- so organize oldest food to the front.
After seven days most open things should be tossed, unless they're condiments. Keep dairy and eggs off the door as the temperature varies. A thermometer is a must and it should read 40 degrees or colder.
From the countertop, cutting board to cutlery, all of them should be disinfected after working with perishables. You can make your own spray with a teaspoon of bleach in two cups of water. Soapy water first, then a bleach-spray chaser.
During preparation of raw meats, use paper towels, not dish towels, and wash hands immediately after using.
Sponge should be rotated out every two days, or microwave in bleach water for two to three minutes.
And finally, remember almost everything you do in the kitchen ends up right in sink, so after food prep make sure you disinfect the sink, the drain and the stopper as well.