Glass jars are no doubt the very best way to proceed in home canning whether it be pressure canning or boiling water bath canning. I would never use metal containers because of the one-time use and most importantly the requirement and expense of sealing equipment in using metal cans.
The Mason jar with its regular and wide mouths with the open threaded neck for the ring and lids that Seal are definitely the best for home canning. Your Mason jar requires only lids each time of use in home canning.You must wash the jars before every use in hot water. The use of a mild detergent is necessary with a complete rinse after such a cleaning. This will not sterilize the jars but it does clean the jars for prolonged water boiling or pressure canning.
However if your are thinking about preparing jams,jellies or pickled items,then it requires sterilization of your jars in the home canning procedure. This is a simple procedure and easily accomplished by placing the empty jars into a boiling water canner. You fill both the jars and canner with hot,but not boiling water, to one inch above the jar mouth. This should be boiled for ten minutes at altitudes of less then 1000 feet and add an additional minute for every 1000 foot change in altitude. I will provide a reference at the end where you can locate a chart on this complete procedure.
The jar requires a good lid and sealing gasket. In the processing of foods the lid gasket seals the jar sealing surface but leaves enough space to allow air to escape from the jar allowing the gasket to form a airtight seal on your home canning jar. I would purchase only the number of lids that you will need in your home canning endeavors for one season. In this way you can be assured that you have fresh lids and gaskets.
Now you have your jars filled and in order to release the air bubbles using a flat plastic spatula,no metal please,insert between the food and the edge of the jar. Moving the jar slowly in a circle,push the spatula up and down to encourage the release and escape of air bubbles.You should clean the rim of the jar removing any particles that would prevent an air tight seal.
You are now ready for action! Proceed to place the lid gasket on to the cleaned rim of your jar and fit the flat metal lid into the metal screw ring and turn it slowly down on to the gasket being careful not to over tighten the lid in this procedure. It is time to process your filled jars and when this is done carefully remove home canning jars with a jar grip remover.
It will not be necessary to re-tightened the lids. The cooling of the jars results in the contents of the jar to contract which in turn pulls the self sealing lid firmly to the mouth of the jar resulting in a high vacuum being formed. The jars should be cooled for twelve to twenty four hours at room temperature in an upright position.
Then it is time to remove the screw rings from the jars and begin testing each lid for the proper seal. This is easily done by pressing the center of the lid to see if it is concave. Then lift the jar by its lid to see if it will come off and if you cannot accomplish and the center does not want to flex up or down you have a good seal and your home canning is concluded.
An excellent chart detailing the exact altitudes and more information on boiling water bath canning can be found at http://www.gardenersgardening.com/boilingwaterbathcanning.html In addition if you want to be informed on the types of tools,jars and other equipment necessary for home canning go to http://www.gardenersgardening.com/homecanning.html