To sterilize canning jar lids, wash them in hot soapy water, and then rinse and dry them. You don't have to sterilize lids in boiling water, which can cause the rubber gasket to thin and prevent a strong seal on the processed jar, according to Country Living.
Scratched or improperly stored lids can result in corrosion on a processed jar. You shouldn't reuse lids, and you should store new lids in a dark, dry, cool location until you're ready to use them. When applying the outer ring over the lid, tighten the ring with your fingertips just until you encounter resistance because over-tightening can affect the seal. Once the lids seal after processing, remove the outer rings and store the jars.