This is my basic jam recipe. It can be used for just about any type of fruit jam (strawberry, raspberry, blackberry, apricot, peach, blueberry, etc.).

Yield: 4 half-pints

4 heaping cups of fruit
1/2 to 1 cup water (depending on natural juiciness of fruit)
1 package no-sugar pectin (= 3 Tbsp no-sugar pectin)
sugar to taste (probably about 1/4 cup)
Pinch of spices, if desired (things like allspice, cloves, cinnamon, ginger, lemon peel can be a nice addition, depending on the fruit)

Chop up fruit so its small enough to be an acceptable "chunk size" in jam. Raspberries and blackberries will break down on their own pretty well; strawberries, apricots, peaches, etc. need to be chopped pretty finely. For marmalade, cut citrus into slivers; no need to cut peel and flesh separately because they will break down some while cooking...

In pot, mix fruit and water.

Heat until mixture comes to a rolling boil that can't be stirred away. If you want to make a more concentrated flavor (necessary for marmalade), reduce heat and simmer until mixture reaches your desired consistency (recognizing that it will still "gel" after you add the pectin).

Warm your jars.

Add sugar to taste. Add it in small batches so you don't accidentally over-sugar.

Add pectin. Boil hard for 1 minute.

Ladle into warm jars.

Process in boiling water canner for 10 minutes.