Growing in Water
Fill the bottom of your container with rocks. Arrange your bulbs on the rocks so the roots is facing down. Fill the container with water until the tip of the bulb is touching the water. Do not allow the bulb to sit in water directly, it will rot easily. Expect blooms in about 3-4 weeks from planting.
Growing in Soil
To start, select a container with drainage holes. Fill the container halfway with a light potting mix. Place your bulbs in your soil root side down. You can place them as close together as you would like. It is ok if the bulbs touch. Add soil until 3/4 of the bulb is covered. Water thoroughly.
Place your bulbs in a cool spot out of direct light until they start to root. If you gently tug on the bulbs each week, they will provide some resistance once they have started to root. Once rooted move them to a sunny spot.
Before your bulbs bloom, water weekly. If planted in water, make sure the roots always have access to water. If planted in soil, allow the soil to dry out about an inch down before watering.
After blooming, monitor your Paperwhites closely. They can dry out in a day or two. So watering more often will be necessary.