A basic backpacking list. I can use this list to stay under 20 lbs and backpack for a week at a time. Many people prefer more than this, and some prefer less.
Personal Backpacking Gear
Backpack 50-60 liters*
2-3 upper body layers
1 windproof waterproof jacket
2 lower body layers
3 pairs of socks (1 that will need to stay dry)*
Sleeping bag (32 degree, actually 32 degree not one that says 32 degree but is really 75)*
Water bottle and or camelbak
Personal hygeine stuff
Hiking boots/Trail Runners/Vibrams
Group Backpacking and Shared Gear
Shared gear are things that you only need one. If you have two people, you can split it among yourself. If you are solo, then you get to pack it all on your own.
First Aid Kit
Spot Locator Beacon
*This is dependent on factors like length of trip and size of your sleeping bag.
** A good Merino Wool or synthetic sock can be washed and dried every night.
*** The temperature will change depending on your location. Watch the temperature reports for the are you will be camping. Take the low temp and then try to get a bag 15 degrees lower than that temperature.
**** Laugh all you want but crocs are great for this. They are lightweight and pretty comfy after having your feet crammed in boots all day.