My Presto canner starts with 4 quarts of water and about 1/2 cup or so of white vinegar. The vinegar will keep the canner clean and help with the odors.
Read you instruction manual for your canner and how much water it takes. You don't want your canner full more that half way once the jars are in. You need to allow for water displacement. (It's nice to know that elementary school science comes in to play.) Remember, you're not doing a water bath, we're using steam to process the jars. Therefore, less water is needed.
No need to have the water hot. The raw meat is cold so the jars are cold. There is so little water in the canner that it heats up quickly and heats up the jars along with it. You can start with cold water and cold jars.
The canner comes with a flat rack with holes in it that sets in the bottom of the canner. If you get a big canner, you'll need to order an extra rack so that you can put the second rack on top of the first layer of pint jars.
My large Presto canner has enough room for two layers of pint size jars. Here you see the bottom layer. I am able to get 9 regular mouth jars in very comfortably. When you're using wide mouth jars, just know that you won't get as many in per layer.