Know Your Ability - If you haven't been hiking or exercising regularly, start with very easy hikes - short with little elevation gain.
Water - Bring one or two quarts of water per hiker. Drink plenty of it, especially on hot, sunny days.
Sturdy Shoes - Wear sturdy shoes, preferably lug-soled for better traction. Many trails are steep and uneven.
Sunscreen - Don't forget it. You can even get sunburned on a cloudy day.
Wear a Hat - A large brim hat will keep the sun off your face, ears and the back of your neck.
Insect Repellant - Keep the bugs at bay.
Light Colored Clothing - On warm, sunny days, light colored clothing can make a tremendous difference.
Bring a Friend - It's always safer to hike with a friend or with a group.
Have Fun! - Stop to smell the flowers, and enjoy the view.