Stinging nettles, Urtica dioica, are native to the northern hemisphere. They are herbaceous, quick growing plants, spreading by roots to form a dense clump of ground cover. As they first pop up out of dormancy in the late winter or spring, they are less than an inch tall, very quickly growing up to eventually 3-5 feet tall when in flower and seed. One happy plant could grow eventually to a 10 foot+ wide patch in full sun to full shade. Nettles are hardy down to around negative 30° Fahrenheit, in USDA zones 4-9. They should be cut to the ground and composted in the fall.
When choosing a spot for your new plant(s), try to find a spot with rich, moist conditions. Here in Berkeley, CA, we mainly grow it under deciduous trees, where moisture is retained more easily. They are not aquatic plants, but they do appreciate lots of water if they can get it. As long as you give them decent soil and watering, they are a very easy and highly nutritious plant to grow.
Nettles are famous as medicinal plants with many uses and nutritive value. We are not going to give any herbal medicine information except to say that if you are pregnant or nursing, or have any autoimmune or medical conditions, you should consult your medical providers before consuming nettles.
Take special care in touching nettle plants as they are covered in silica-tipped hairs which cause irritation for most people. This can include itching, rashes, stinging sensations, etc that can last from minutes to days depending on skin sensitivity, exposure, etc. It is useful to wear close toed shoes, rubber gloves, long sleeves, and pants when harvesting or pruning nettles. You will want to collect the nettle leaves before the plant flowers in the spring or early summer. After it has flowered, it is considered toxic!