What's the best time and method to add raisins to bread dough

If you're adding them to a recipe that doesn't already call for them, I would recommend pre-soaking them, so that they don't soak up the liquid that's already in the dough. Cover them in warm water (or some mixture of water/juice/brandy etc if you want to add any of those flavors) for about 30 min, then drain and add them to the dough while you're mixing it. If you'll be kneading the dough vigorously, you can add the raisins near the end to make the process less sticky.

It depends on the type of bread, but if doing a wet dough I let the raisins soak in the liquid and add the liquid and raisins together