If you shop early enough you will find a large collection of Paperwhite bulbs in late fall. They get bought out quickly, so plan ahead if you want to buy them. Sometimes you can get lucky enough to find a few marked down in November. Paperwhites are known as the easiest bulb to force inside because they don't require a long cold spell in a cellar or a fridge.
First you need to find a container that is tall and big enough to to hold gravel, stones or rocks that you will need to place the bulbs on. You may want to use a little more stones or gravel than I used if you have more available. You can also find suitable containers cheap at your local dollar store. Next you want to fill the water up just to the top level of the stones. If you put too much water your bulb may rot so be careful. If you need ideas for containers you can simply google paperwhites, or do a search on Pinterest.
Then you place enough bulbs on the surface to cover the diameter of the container or vase. Don't worry if the bulbs touch. I am going to put this container in my laundry room that is not heated and dark for a week. I am doing this because the instructions said to do so. So be sure to follow any directions that come with your bulbs.
After a week a good root system should have developed and the bulb should show signs of growth. At this stage you want to set the container in a warm room. It should grow and bloom in a few weeks. Once you have mastered how to grow these bulbs you can try ones that need a few weeks of cold to mimic winter like tulips and even daffodils. It is best to start with less bulbs at first to make sure you have the technique down because bulbs can be expensive. Forcing bulbs in the winter is a great way to bring a touch of the garden indoors and keeps the idle hands and mind of a gardener occupied until spring starts.