Keep an eye on the sunflowers in fall. Perhaps the easiest way to tell if the seeds are ready is if they have black and white stripes, rather than a solid color. Other signs include fallen petals and brown coloring on the backside of the flower.
Cut the flower head off the plant, along with approximately 12 inches of the stem. Pruning shears work well for this job.
Put on a pair of gardening gloves, and hold the flower over a clean, empty bucket. Rub your hand firmly over the seeds to dislodge them from the flower.
Soak the seeds in salt water overnight if you plan to eat them. Use 1/4 cup of salt for every 2 qts. of water. Strain the seeds from the water, and lay them out in a thin layer on clean paper towels to dry. Bake the seeds at 300 degrees Fahrenheit for 35 minutes.