Equipment Checklist
When planning what equipment you're going to bring on a backpacking trip the most important thing to keep in mind is how much your equipment weights.  Obviously lighter is better.  Use strong digression when deciding what you're going to bring and try to keep your luxuries down to a minimum.  An extra pair of pants is nice to have but definitely not necessary.  The two areas I usually splurge are sleeping comfort and food.  Remember that some resources like soap and toothpaste can be shared.
BASIC EQUIPMENT Backpack Tent Sleeping Bag Sleeping Pad Hiking Boots or Shoes (waterproof) Knife, Fork, and Spoon Water Bottle Plastic Cup (light and durable) Flashlight (small and bright with fresh batteries!) Light Jacket, Sweater, or Pullover: 1 Long Sleeve Shirt: 1 (for extra warmth) T-Shirts: 2 or 3 Jeans: 1 Shorts: 1 Underwear: 1 per day Hiking Socks: 1 pair per day Rain Poncho (for bad weather and the Mist Trail) Change of Clothes (left in car for drive home)   OPTIONAL BASICS Book Backpack (for the Half Dome day hike) Hat (to keep sun off face / hair back) Extra Bottoms (jeans or fleece) Ground Tarp (plastic sheet to sit on) Camera and Film (disposable cameras are light) Large Zip-Loc Bags (for wet items, dirty clothes) Whistle (for bears) Ear Plugs (for loud tent buddies) Beer (sneak it into your buddies backpack ;-)   FIRST AID SUPPLIES Moleskin (to protect your feet from blisters) Tylenol (or other pain killer) Antihistamine Antacid Tablets	PERSONAL ITEMS Personal Medications Sunglasses Sunscreen Lip Balm Insect Repellent Toothbrush and Paste Dental Floss Soap (in a zip-loc bag) Shampoo (free samples or very small bottle) Conditioner (free samples or very small bottle) Comb or Brush Wash Cloth (in a zip-loc bag) Small Bath Towel Toilette Paper Tampons   GROUP GEAR Water Filter: 1 - I have this Rope 50' : 2 (for hanging food) - I have these Backpacking Stove: 1 - I have this Stove Fuel: 2 bottles - I have these Pots and Pans: 2 or 3 - I have one Backpacking Grill: 2 or 3 - I have one Oven Mit: 1 - I have this Sponge: 1 - I have this Cigarette Lighters: 3 (must stay dry) - I have two Paper Towels: 2 rolls (for cleaning, starting fires, etc) Heavy Nylon Cord: 1 roll - I have this Sturdy Paper Plates: 1 per person per day Plastic Garbage Bags: 2 - I have these