Know the Lay of the Land
You wouldn't go to Disney World without knowing the weather, the peak season and how to use a FastPass. Likewise, don't embark on a family camping trip without doing some solid research; unlike riding Space Mountain, being unprepared in the wilderness could be a life-or-death situation.
Familiarize yourself with the area before you go as each terrain has its own challenges. Pitching your tent on a sandy campground is different from pitching it on hard earth; a rocky site may mean lots of hiking prior to arrival. Whatever the case, prior knowledge is key.
Get to know the campsite on arrival. Check for hazards like riverbanks, cliffs or rotted branches. Know who and what is around you, and don't assume everyone in the Great Outdoors is friendly. Keep doors locked or zipped at night and when you're gone.
Research the weather before your trip; call the ranger stations where you'll be staying to check on potential dangers such as flood or hurricane paths. Transitional seasons (spring and fall) can bring swings in weather, and mountainous regions can experience extreme highs and lows.
Teach your family to notice landmarks. As in the movies, everything can look alike when you're lost in the woods. Seek out identifiers at your campsite and on hiking trails.
Know the locations of ranger stations, refuge areas and local hospitals. Hopefully, you won't need to visit, but if you do, time may be of the essence.