Question: Is it necessary to sterilize jars before canning?
Answer: Jars do not need to be sterilized before canning if they will be filled with food and processed in a boiling water bath canner for 10 minutes or more or if they will be processed in a pressure canner. Jars that will be processed in a boiling water bath canner for less than 10 minutes, once filled, need to be sterilized first by boiling them in hot water for 10 minutes before they're filled.
Reference: National Center for Home Food Preservation
Of course you should still wash them in warm soapy water and keep them warm until ready to fill. Kat