Seeds can be bought which produce varieties that are far superior to the wild dandelions that grow wild in most gardens, alternatively just transplant them to a suitable patch.
The most important thing you should ensure if you do grow dandelions in your garden is to deadhead them before the flowers turn to seed – else you will have far more plants than planned and all in the wrong place!
Dandelions can be propagated from seed, or by taking root cuttings.
The leaves can be used in salads or cooked like spinach, and they are rich in vitamins and minerals. The roots can be used as a coffee substitute, and wine can be made from both the flowers and the roots.