Jam is easy, providing you haven't anything else to do that won't wait!.
First of all thoroughly wash jars and lids, rinse well and put into a warm oven to dry and sterilise.(put lids into boiling water for a minute, then remove with tongs and put into a clean tea towel if they have plastic in them)
To make the jam....Have one pound of raspberries to a pound of sugar, or the metric equivalent, put into the preserving pan (or very large saucepan) add the tiniest bit of water and bring, very gently, to a simmer. Let them simmer for five minutes or so, then add the sugar. Keep stirring with a wooden spoon until you are sure the sugar has dissolved (it doesn't feel "scratchy" on the bottom of the pan)
Bring to rolling boil, stirring frequently for fifteen minutes, then test. Take the pan off the heat and on a previously cooled saucer (put in the fridge before you started) put a small teaspoon of your jam, when coolish. give it a push with a fingernail. if it wrinkles your jam is ready to pot. If not, shove it back on the heat and try again five -ten minutes later. When done pour or ladle jam into a jug and fill the hot jars. Using a thick tea towel to hold the jars put the lids on.
I hope it goes well!