OK, here is a suggestion:
Monday: Arrive in YNP. If you are coming from SD, you will probably get in pretty late so not much time today. Check to see if they are still having Ranger programs, there may be one in the evening.
Tuesday: Make this your geyser day. Go to the Upper Geyser basin and Old Faithful. Check in at the Visitor Center and write down the eruption times for the predictable geysers on the brochure available at the desk. (50 cents). Try to work your walk thru the basin so you can see some of these geysers. I usually start by going behind Old Faithful on the path to the left side of this geyser, crossing the bridge and up onto Geyser Hill. From there I head down the geyser basin to Morning glory pool (pit toilet here!) and go back toward Old Faithful on the paved path. I like to eat lunch at the Lower General Store which should still be open then. It will be the first store you come to on the right (well, the geysers are on the left, lol) as you head back to the Visitor Center. After you see this area, hop in the car and head north from Old Faithful on the loop road. Do the Firehole Lake Dr. (on the right) and go almost to Madison Jct and turn left into Firehole Canyon Dr. This is one way headed back South. (If anyone needs a pit stop, go on to Madison Jct, there are flush toilets there.) Rejoin the loop road and pick up Fountain Paint Pots, Midway Geyser Basin, Biscuit Basin and Black Sand Basin. Head back toward Grant. Stop at Keppler Cascades.
Wednesday: Make this your Canyon Day. Head north to Fishing Bridge. Park and walk across looking for wildlife. Continue North to LeHardy Rapids and then enter Hayden Valley looking for wildlife. At Canyon, you have a couple of choices. If you want to go to the Visitor Center first, go past the entrances to the South and North rims, and tour the VC. Then work your way back on the South and North rims. If your husband's back is bothering him, the easiest access and view is Artist Point on the South Rim. It is level right out to the view. The viewing platform has some steps, but you can actually see just as well from below. Return to Grant picking up Mud Volcano on the way. If you want a short, level hike, do Natural Bridge. It is an old road bed.
Thursday: This will be a long drive day. If you want you can interchange it with Wednesday. Drive North toward Canyon (stop for pit stop at VC) and cross over Dunraven (this road closes Sept 22 but again check at Canyon VC for information) to Tower Fall. Stop there and at some of the overlooks north of the Fall. At Tower Roosevelt Jct, turn Right into Lamar Valley. Drive out there and stop if you see people with cameras with long lenses and spotting scopes. Return to Tower Roosevelt Jct. Head toward Mammoth. If your time is running OK, do Blacktail Plateau Dr and Petrified Tree drives. Many see black bear back in here. I never see squat! Head on to Mammoth. Walk the lower Terraces. The best bathroom here is the new one by the bus parking lot and the gas station. Drive the Upper Terraces. Start south toward Norris. Do Norris if you have time (I doubt it!) and return to Grant.
Friday: Use this day to revisit anything you want to see again, or to visit things you have missed (Norris Geyser Basin? Virginia Cascade Dr?).
Saturday: Head for home. If you are not pulling a trailer, I would go out the NE entrance and over Beartooth Highway to Red Lodge. THis will be weather dependent, so ask at Grant on Friday how things look over Beartooth. This is Highway 212 on the map. The bad thing is that the road between Canyon and Tower is supposed to close today, so that would mean going either out the East entrance to Cody, cutting up Chief Joseph Scenic Highway toward Cooke City and then onto Beartooth OR going around the west side of the Loop Road (Norris -> Mammoth -> Tower Jct).
I am sure you will have a wonderful time!!
(editing to add: Laughing at PeachBelle because we were typing and thinking at the same time! Where is thbergs and the ice cream recommendations?)
Edited: 2:31 pm, July 19, 2012