Understand the difference between hiking in the Grand Canyon and hiking the routes you're used to. The Canyon hikes are demanding. They'll test your endurance, both physical and mental. Be ready to respect your limitations.
Learn about hiking the Grand Canyon through the National Park Service's informative website. The NPS constantly updates its free online Grand Canyon Hiking Guide with updates and information. The Hiking Tips section has seasonal information for summer and winter and trail closures are posted in real time. There's a very informative "Prepare for Backpacking" video on the site, as well as numerous "Hike Smart" podcasts.
Get an accurate, recent map. A great map is a planning essential, and it'll help you orient yourself as you hike. The Grand Canyon Association sells topographic maps of suitable quality.
Know where to find water along your route. If you'll be purifying your own water, make sure you know where the sources are. Purified drinking water is only available at six locations within the Canyon. Some of these sources are seasonal, and all are subject to broken pipelines and other cutoff-causing damage.
Obtain your permit from the Backcountry Information Center. The National Park Service requires a permit for any overnight activity in any season. Only a handful of developed campsites are exempt (those on the North Rim, South Rim and Tuweep), and your hiking trip will almost certainly not focus on those sites. Rangers are sticklers for the details of the permit, and you'll be penalized if your permit doesn't match your stated trip leader, itinerary, party size and dates.
Keep your permit safe -- it must be posted in plain view once you make camp or you may be in for trouble with the NPS rangers.
Know the rules. There are many rules for hiking the Grand Canyon, including the trip length, party size and usage areas. By obtaining a permit, you've agreed to follow every one of these rules -- and they all carry penalties for noncompliance.
Save room in your packing for a stove if you want to cook hot meals. Fires are prohibited throughout the backcountry. During winter, a camp stove is a vital survival tool.
Decide whether to bring a tent. If you're traveling during winter or during the July/August rainy season, you'll probably need a tent; during dry months, you may decide to save weight by bringing only a rain fly or a bivy sack.
Do one local hike with your fully-packed Grand Canyon bag before you set out on your hiking trip. This will tell you immediately if you've made any grievous over-packing errors.
