This sounds like a delicious, and simple, homemade jam. The missing part of the instructions involves canning the jam, which must have been assumed and so not included.The nine jars mentioned are the glass pint sized jam and jelly variety. Fill the prepared (boiled) jars almost to the top, screw on the lids, and submerge in boiling water for 10 minutes. Remove, let them cool and then press the middle of the lids. If they don’t give, the jars are sealed. Any that have springy lids will need to be refrigerated.
For more information on home canning visit National Center for Home Food Preservation.