Olive oil is probably the healthiest of all oils. It has lots of monounsaturated fat, which is good for you, and less saturated and polyunsaturated fats than vegetable oils.
Unlike oils that are processed from hard seeds using heat and chemicals, oils from the fruit of the olive are soft pressed and healthier.
It is sensitive to light and heat however, so use it in dressings, but it will lose it’s healthy properties when heated.
Peanut oil is more tolerant of heat than olive oil and other oils, and is suitable for frying. The peanut taste of the oil complements some foods very well.
Peanut oil is higher in monounsaturated fats than most vegetable oils, but opinion ios divided on whether it is healthy, because some peanut oil could be contain traces of a carcinogenic mold that some peanuts have.
Canola oil doesn’t really have a flavor and is suitable for frying. It is high in monounsaturated fat and has some omega-3 fatty acids.
The safest canola oil is organic, expeller-pressed available in the health food stores, and most grocery stores.
Always keep oils in a cool, dark place, ideally in the fridge.