Many people see dandelions as weeds, but their leaves and roots actually taste great. Although I will focus on the greens, do not think dandelions are limited to these.
You can also blanch dandelion and serve it like spinach. For this, you can use either the young or the old leaves, though you still have to make sure the plant isn't by a road or has been sprayed with pesticides. If you do not take this precaution, you risk consequences from bad taste to sickness. Good luck picking your dandelions instead of killing a good tasting, nutritious, herb.