This applies to ALL kitchen utensils, and your preparation surfaces as well such as cutting boards, countertops, etc. My rule of thumb is to wash anything that comes into contact with flesh/blood (from the animal or if you injure yourself) as soon as you're done using it to minimize cross-contamination risk. And of course, the most important kitchen tool is yourself, so ALWAYS
remember to wash your hands too!
Seriously, if you're working in the kitchen, washing your hands is automatically the first thing you do every time. First, rinse your hands under warm water. Then, take some soap and start washing them. Rub them together and over one another vigorously. Don't forget to clean under the nails! Rub your fingertips at the nail against your palm for several seconds. Once you're done, rinse the soap away under warm water and then dry your hands with an air dryer or with a clean towel/napkin/etc.
Honestly, hand washing is one of the easiest ways to prevent some really
nasty diseases and it takes less than a minute. ALWAYS WASH YOUR HANDS BEFORE WORKING WITH FOOD!
Also, ALWAYS remember to turn the oven off when you're done using it!!!!!