Yes, the seeds need cold stratification, probably for about 3 months. If you don't understand that, then research it. You'll also need to grow them in pots until well established, as they are easily disturbed in the ground when small plants. Then you'll need to plant out to very acid, very well drained soil: peat, gravel and not much else. My observation of bilberry plants in the wild is that a lot of them don't fruit, so you might need an acre or two to get much yield. They seem to grow well as understorey in low-density conifer forest, so the occasional pine or spruce might help.