Summarize:

Although experienced nettle harvesters often go bare-handed, this isn't just because they know how to avoid stings. Many of them have become resistant to the stings over years of exposure, while others enjoy the sensation. Consider wearing gloves, or plucking the nettles with tongs. Nettle is a traditional treatment for arthritis, and there's some scientific evidence that it works. So if you suffer from arthritis in the hands, getting stung may actually reduce your pain! Mature nettles may contain calcium oxalate crystals, which can trigger gout episodes or irritate the urinary tract. When picking nettles to eat, look for young plants that have not yet flowered. Look for these in early to mid spring in most areas. Burning nettle, a very similar plant often mistaken for stinging nettle, can germinate anywhere from late fall through early spring. In mild coastal climates, it may flower year round. Any of these processes will neutralize the nettle and make it safe to eat. The two most common uses for nettle are nettle soup and nettle tea.
Considering protecting your hands. Harvest young nettles. Cook, freeze, or dry to remove the sting.