There is a National Sunflower Association

And they taught me how to harvest the seeds from the "Mammoth Sunflower" I grew (I received a great bounty of seeds from my sweet Secret Santa last year, including sunflower). I started this sunflower in a pot so its growth was stunted-- it only got to 4-ish feet tall when this variety can grow to 10-12 feet tall. I can't wait to plant some directly in the ground next season and have a whole army of these things. And then I can throw a harvesting party.

Here's my Sunny. His head got super-droopy in July:

You can see the bald spot where I plucked off sunflower seeds now and then for a taste. Raw sunflower seeds are nice.

 I beheaded him and brushed off all the florets:

 All those tightly packed seeds. Magical.

The sunflower was about nine inches across.

This is what was left of the stalk:

 I found that it was pretty sturdy after pulling it out of the ground, and have since stripped off the leaves and turned it into a support for my tomatoes. After waving it around like a weapon a few times.

 The shucking process took a bit longer than I expected. 

About half of the seeds I collected proved to be empty after a squeeze (I guess the bees were not so busy this spring), but I had a good couple handfuls of the seeds. After cleaning them and soaking them in salt water per the National Sunflower Association's instructions, I dried them. Didn't get a chance to roast them before gifting them to my friend Claire, but she seemed to approve of them as they were.

It was worth the effort of the last few months. Enjoyed a pretty sunflower, then got tasty seeds and a new pole for the still-going tomato plants to hang onto. All good.