Does anyone really need a photo or a description to help them identify stinging nettles? I tell you what; if you're unsure whether a plant is a stinging nettle or not, brush up against it. If it hurts, it is one. Stop whimpering. Find yourself a dock leaf and crush the juice into the sting, it'll soon relieve the pain.
Nettles don't form such deep root systems as docks and so are easier to remove in that sense. However you have to wear gloves and a long-sleeved shirt made of fairly thick material, otherwise you'll end up with very sore hands and arms. But once you've pulled them up, you can throw them on the compost heap, make weed tea, or put them to many other uses.
I love to make them into delicious soup. I've also made them into soap. The least application of heat and their stings are totally disarmed - I saw Ray Mears on TV wilt them by holding them directly over a fire, and then he ate them. They're best in the spring; once summer gets well advanced they seem to become gritty, however well you wash them.
You can also make nettle beer, apparently, by boiling 2lb of nettles with the rind of 2 lemons and 1 gallon of water for 15 minutes. Strain into a container and add the juice of the 2 lemons, 1lb of sugar and 1oz cream of tartar. When cool, add 1oz yeast and leave in a covered container in a warm place for 3 days. Then strain into bottles, cork down and wire, and leave for 1 week before drinking. I've never tried this recipe, which comes from Marguerite Patten's out-of-print book 500 recipes for Home-Made Wines and Drinks, but next spring I'll give it a go.
There's even a website dedicated to nettle appreciation, where you can read about the importance of nettles to native British wildlife, and the uses of nettles as food, medicine, clothing (eep!) and in the garden. I wouldn't go that far, but I feel more kindly towards nettles than I do towards docks, for example. Not so kindly that I won't rip them out of my allotment when I find them. But kindly enough to appreciate the patch in the farmer's field behind our house. They're a useful resource, as long as they're growing on somebody else's land, not mine.