Daffodils and jonquils are bulbs that store energy to become wonderful spring flowers. I love to plant them because they're easy to care for; wildlife won't eat them and more recently, now that I have honeybees, they're a favorite spring pollen source. Regardless if you're planting new bulbs, or ones that you've divided, the process is the same:
Dig a hole about 4-5" deep, allowing for 4" between bulbs.
If you don't mind moving bulbs more frequently, plant them closer. If you prefer them to be in their spot for several years, then give them more space. Apply bone meal to the bottom of the hole; bone meal is a good source of nutrients, which can be hard to provide from the top. Cover bulbs with soil; water. I would also pop a popsicle stick somewhere so you can more easily remember where you planted them. You can plant other plants that bloom later in the season on top of your bulb area as long as they are shallow-rooted.