Compass
Yes, global positioning satellite (GPS) systems are all the rage, but if you learn how to read a compass you can increase your chances of getting back to civilization in the event you get lost and keep all the equipment you need in a pocket. A simple, old-fashioned compass has been an essential navigational aid for centuries and isn't subject to power failures or satellite transmission interruptions.
Map
GPS is no substitute for a detailed map of the area in which you are camping, either. A map is especially vital for backcountry camping when you may be separated from others by miles and not see people for days. It can be ridiculously easy to get lost even in a place you've camped dozens of times. The best advice is to get to get a map with a scale over 1:100,000 as this will provide detailed features of the land to better ensure navigating the trail correctly.
Flashlight
A flashlight you can hold in your hand may be needed to read that compass or map in the middle of the night. You'll always want to be prepared with a flashlight any time you go off away from the campsite. A flashlight also comes in handy if your other means of illumination fail.
Tent
Unless you totally want to rough it by sleeping on the ground without shelter, the tent may be your most important piece of equipment. You'll find an enormous variety of tents nowadays, some of which may seem more luxurious than some houses. It is easy to go overboard and get a much bigger tent than you need, but you only need enough room to sleep every member of your party and enough height to allow everyone to sit up at the same time.
Sleeping Bag
The next most important piece of equipment is your sleeping bag. Even the most comfortable patch of ground is no match for a lumpy bed, so don't spare the expense here. Open the sleeping bag up and crawl into it at the store, if the store allows it. You want it to be comfortable as well as a good match for the weather. Don't go for too much down and fleece if you do most of your camping in the south in summer, but go in the opposite direction if you usually camp out where the temps drop substantially at night.
