As far as your trip to Grand Canyon, look up and book NOW for Canyon Dave. My wife & our 2 daughters went west about 6 years ago, found Canyon Dave thru a tour book, sounded neat, and it WAS!!!!!!
Dave grew up around the G.C., knows it intimately and is an absolute wealth of knowledge about it. We were booked for the afternoon tour, which in our case (it was about October, i think?) ended just about sundown. Also fortunately, we were the only ones to have booked that afternoon, so it was just the four of us, and Dave. It helped a lot that we were not (as Dave so eloquently put it) 'duds'; we're all very inquisitive, love science and nature, and asked a lot of questions. Since we had shaved a couple school days off the girls' calendar to make the trip, one was required by one teacher to write a report, based on the trip. Dave's tour made my daughter's report a slam-dunk A!
http://canyondavetours.com/