Conifers can be planted throughout the year, but it is best to plant them in the late autumn or winter, as long as the ground is not frozen or waterlogged.
They should be planted in full sun or partial shade, and are tolerant of most soil types, but will benefit from having compost or manure tilled into the soil prior to planting.
Conifers also need decent draining, so do not plant them in very heavy clay soil or else you will risk drowning the plant.