Below are links to various sites that I feel are very useful, interesting, and otherwise worthwhile to share.
All Hikers - Richard Perry has assembled information that those planning a trip to Grand Canyon will find both useful and interesting.
AZventure in Hiking - An extensive page devoted to links on the Grand Canyon- including trip reports. A lot of research went into this amazing resource. Go to Todd Tidyman's home page to find information for the entire state of Arizona. Unfortunately, there are quite a few broken links but many of the active links make up for those.
Frank and Anne's Canyon Country Hiking & Camping Notebook - A treasure trove of information about Grand Canyon and many natural areas throughout the Southwest. Also, if you are interested in prehistoric Indian rock art, you'll love this site! The link above takes you directly to the Grand Canyon pages within the site, but explore around to find much more information on many spectacular areas.
Grand Canyon Explorer Home Page - The "unofficial" but fabulous site showing all things Grand Canyon! Exquisite photography and a wealth of information makes this site one of the finest out in cyberspace!
Grand Canyon Field Institute - A wide variety of courses are offered, including Geology, Natural and Human History, Archaeology, Botany, Backcountry Skills, and much more! Education and excitement all rolled up into one place! Something for every skill level.
Grand Canyon Hikers and Backpackers Association - "The mission of the Grand Canyon Hikers and Backpackers Association is to promote, encourage and advocate the interests of the hiking and backpacking community in the regions of Grand Canyon."
Grand Canyon Hikers eGroup - Are you addicted to the Grand Canyon? Are you planning a trip here and have some questions to ask the veterans? Then this is the site for you. Join the Grand Canyon Hikers eGroup and share your passion with others who feel the same. Fun, fun, fun!
Grand Canyon National Park - THE CANYON! The best photos and paintings in the world can only offer glimpses of this geologic masterpiece. It must be seen to be believed! Spanning a distance of 277 miles, with an average depth of one mile and width of ten miles, Grand Canyon is one of the seven natural wonders of the world and a World Heritage Site. With elevations in the park ranging from 9000 feet on the North Rim all the way down to 2400 feet at the Colorado River, it is wise to research your itinerary to prepare properly for the conditions you are likely to experience. Information on reservations, permits, activities, tours and much, much more. This comprehensive site has links to many other related sites as well.
Download a copy of the Backcountry Permit Request Form here, and you can mail or fax it in to Grand Canyon. Simply follow the directions on the permit request form. It is in PDF format, so you will need the free Adobe Acrobat Reader to view and print the file.
Keep up-to-date on trail and road conditions and closures via Grand Canyon's Critical Backcountry Updates RSS feed.
Grand Canyon Treks - You can never read too many trip reports, and this site is a valuable resource for them. Mike Mahanay's site has a wealth of information on hiking and history at the Grand Canyon. If you planning a backpack trip here, I would definitely recommend that you take a look here!
Grand Hikes with Bob's Rock Shop - Here is a site for those of you who are rockhounds and amateur geologists, as well as those just interested in knowing what forces created this magnificent canyon cut by the Colorado River.
Hiking the Grand Canyon: The Corridor Trails - For those of you planning your first major backpack trip in the canyon along the North and South Kaibab and Bright Angel Trails, I highly recommend this video. Nothing quite gives you idea of what you will encounter physically and mentally than actually hiking here, but this video is the closest you'll come.
Hiking with Children - This is not a Grand Canyon site, but it does have some great information for hiking with children.
Travel with Kids - This particular article is on hiking the North Rim with kids. The site includes many other destinations in the United States and all over the world.
Recreation.gov - An excellent government site showing recreational areas for the entire country with contact information and links to the respective agency. This comprehensive website covers all aspects of recreational activity: auto touring, biking, boating, camping, climbing, historical/cultural site, educational programs, fishing, fish hatcheries, hiking, horseback riding, hunting, lodging, off-highway vehicle access, picnic areas, recreational vehicles, museum/visitor centers, water sports, wilderness areas, wildlife viewing, and winter sports.
WalkingAndHiking.co.uk - "Whether on a short stroll through the woods or a five peak challenge, we offer great tips and advice on keeping fit and safe." Not a Grand Canyon site but rather one that provides information for those ready to embark on a walking or hiking venture. You'll find tips on equipment, boots, and the benefits of joining a walking club, as well as advice on hill walking, long distance walking, and scrambling.