first you'll need some canning supplies. i found a large canning pot and all the jars and utensils at target and picked them up. except for purchasing more jars, it is a one time purchase that you won't need to make again. you'll most definitely need a large canning pot, the large tongs for pulling out the steaming jars, canning jars and a funnel.
mixed berry jam
5 cups crushed blackberries, strawberries, and blueberries
7 cups of sugar
1 (1 and 3/4 ounce) package of fruit jell pectin (i used "sure jell" but "bell" would work as well)
carefully measure out the berries. i don't like huge clumps of fruit so i really crushed my fruit until there were very little pieces. put the berries into a large cooking pot.
measure sugar into a large bowl.
add the pectin to the berries a little at a time, stirring constantly.
heat on high, stirring constantly, until the mixture comes to a full boil.
add sugar all at once, stirring
bring mixture back to a full, hard boil, stirring constantly.
boil for one minute.
remove from heat and ladle into clean, hot 8 oz jars, leaving 1/4 inch space at the top. (before i heated the berries, i filled my kitchen sink with very hot water and put the jars into this until they were needed.)
wipe the rims of the jars and put the canning lids and rings on tight.
place each filled and sealed jar into the canning jar filled with very hot water. make sure the water is one inch above the jars.
process (let sit) in a boiling water bath for ten minutes.
remove the jars and set them upright on a towel to set for 12 hours.