The original recipe calls for 9 cups of crushed raspberries and 6 cups of sugar. I've successfully cut the sugar to 5 cups with good results but you can go with whichever measurement you prefer. The jam will probably be a little thicker if you use the greater amount of sugar. I like more of the raspberry flavor to come through rather than just a "sweet" flavor, so I prefer to cut the sugar.
Also remember that if you pick some of the raspberries a smidge under-ripe, they will contain more natural pectin which will enable the jam to "set up" to a firmer consistency than if you use all dead-ripe berries.
Okay, grab your ingredients and utensils and let's make some jam.
Combine 9 cups crushed raspberries with 5 cups sugar; bring to boiling, stirring occasionally until sugar dissolves.
Cook rapidly to jellying point (220 degrees). This should take somewhere around 45 minutes. As mixture thickens, stir frequently to prevent sticking.
Ladle boiling hot into sterilized jars leaving 1/4" head space. Adjust caps and put in boiling water bath, 10 minutes for 1/2 pints and 15 minutes for pints.
You should get about 4-5 pints with maybe a "taster" dish left over. Enjoy!