Note: You can use either white or milk chocolate, or chocolate bark. My favorite is Ghirardelli Dipping and Candy Making Bars (both milk chocolate and white). http://ghirardelli.com/products/bars_dipping.aspx You can find them at Sam's around Christmas.
Melt the chocolate in the microwave, stirring frequently until melted. Mix in sunflower seeds. I use roasted, salted seeds. Look on the package for ingredients. I try to find seeds with only salt added. Some brands add lots of other things (including MSG...yuck). I like the ratio of 2 parts chocolate to 1 part seeds, so for each pound of chocolate I used, I stirred in 8 ounces of seeds. But you can do whatever you like best. My MIL likes more chocolate. My mom likes more seeds.
Drop by the teaspoonful onto wax paper and let harden. Easy peasy! They last for at least a couple of months in an airtight container. I do not recommend freezing.