If you are planning a Rim to Rim hike at the Grand Canyon and planning to camp during the hike, these are my suggestions for planning accommodations in advance:

• Driving to the Grand Canyon would be much better than flying, since you may want to need bring two types of camping equipment. If you choose to camp on the South Rim before the hike, you will want a larger tent, better sleeping bags, cooking equipment, etc. Mather Campground is really nice, it is close to a great Marketplace with food and hiking supplies. The weather in the summer is usually perfect on the rim, the temperatures are moderate, very slim chance of rain, and there are no bugs at night.
• Select a Date in the middle of the week, like a Tuesday or Wednesday for the overnight at the bottom of the canyon. That way, camping reservations, duffel service, and dinner at Phantom Ranch is not as crowded.
• Fill out and file the Back Country Permit (see link below) to see if you can get the camp site for the night(s) you have chosen.
• Once you know that you have the camp site at the bottom reserved, reserve Mather Campground for 2 nights before you plan to hike plus the time you will be hiking to the bottom so that camp is set up when you come out of the canyon. The rates are reasonable, and the campgrounds are really safe. We have never had anything touched or taken while we were gone. It is also nice to leave vehicles at the camp site and take the free rim bus from the campground to the place you will catch the shuttle to the North Rim. You might even be able to catch a rim-to-rim shuttle from the Mather Campground bus stop.
• If you are not camping on the south rim, make sure you have a reservation for the night you come out of the canyon. You may be exhausted and the less fuss and detail, the better.
• Schedule the shuttle ride, duffel service, dinner and box lunches at Phantom Ranch. You can also choose to use the duffel service just one way, so you could carry your equipment down and have the mules carry it up for you if you need your camping equipment on the North Rim.
• Camping at Bright Angel Campground near Phantom Ranch in the summer is fantastic, but the temperatures at night can be in the 80s, so traditional backpack camping equipment may be too hot and uncomfortable. A minimal screen tent or mosquito shelter might work better than a tent for the extreme heat at the bottom of the canyon: https://www.rei.com/product/728960/mombasa-defender-mosquito-net
• You may also want a tarp for rain, but in that heat, the rain feels wonderful, and the air is so dry that nothing remains wet for any length of time. Shoes and electronics can be kept dry in a day pack.

Camping, Lodge and Hotel links:

SOUTH RIM

Mather Campground (South Rim)

https://www.nps.gov/grca/planyourvisit/cg-sr.htm

South Rim Hotels in Tusayan
(Red Feather Lodge and Holiday Inn Express – are clean and acceptable)
https://www.google.com/maps/search/tusayan+AZ+hotels/@36.0378345,-112.1896155,12z/data=!3m1!4b1

NORTH RIM

North Rim Camping

https://www.nps.gov/grca/planyourvisit/cg-nr.htm

North Rim Lodge

https://www.grandcanyonforever.com/lodging

Duffel Service (Mules) from the South Rim

https://www.grandcanyonlodges.com/lodging/phantom-ranch/

Bright Angel Campground (near Phantom Ranch)

Back Country Permit:
https://www.nps.gov/grca/planyourvisit/upload/permit-request.pdf