If you do not have your own raspberry bushes then visiting a pick your own, buying fresh or frozen is the way to go.
As well as using it on bread or toast there are numerous dishes you can add it to: Thumbprints, roly poly, Bakewell tarts, biscuits, brownies, all sorts of desserts etc....
To test for a set: before starting to make the jam put a couple of saucers or small plates into the coldest part of your fridge. When you think the jam has reached setting point, place about a teaspoon of the jam onto one of the cold plates and leave for one minute. Then gently push your finger through it. If it wrinkles / rises up your finger nail it is ready.
If you are new to jam making I have a recipe posted that shows and explains about the various equipment I use.