Hiking is one of the most accessible and fun outdoor activities around. If you can walk, you can hike. Hiking can be a social activity, and a great way to spend time in nature and get some exercise. Avid hikers consider hiking the best way to explore remote places, without the distractions of vehicle noise.
For a basic day hike, you'll need comfortable shoes or hiking boots, a pair of synthetic (non-cotton) socks, shorts or pants, and preferably a synthetic or non-cotton shirt. Depending on the weather, you may want to wear multiple layers to keep you warm and allow you to adjust to the day's temperature. You may want to consider a pair of synthetic underwear to prevent chafing on the inside of your legs as well. In addition to clothing, you'll need to bring along water, and some food. You also may want to wear a hat or visor to protect you from the sun or rain, and sunscreen. Depending on where you're hiking, it can be a good idea to bring along some bug spray as well.
For longer hikes, the classic '10 essentials of hiking' include: a map, compass, flashlight, food, water, water purification, extra clothing, rain gear, matches, sun protection, pocket knife, and first aid kit. These are all great to have, especially if going on a multi-day hiking and camping trip. You may also want to bring a whistle along, it's a great tool for alerting others if you're in danger.