Just take the long drive a day at a time and don't plan where you stop. We constantly had the Milepost open as we drove. It will tell you about every mile you drive and what attractions there are. If you only drive 100 miles and see something of interest, that's your stop. It's really very easy to do.
We used Church's book solely for campground information. It's much more accurate than the Milepost and a little more up-to-date. However, keep in mind that every year campgrounds will close for various reasons but there will always be a spot to pull over for the night.
The same for fuel stations. Drive on the top half of your tank just in case the next station is closed.
The only reservations we made were for the July 4 weekend and 5 nights at Teklanika campground deep in Denali National Park. We made those reservations only a few weeks prior when we knew better when we'd get into the area. As it turned out we were a little early for Denali so on a whim we boondocked nearby the previous night and pulled into Denali early morning the end of July and easily secured a spot for our 40' motorhome in Denali's Riley Creek campground for 5 additional nights in Denali.
Don't overplan and you'll have a more relaxing trip!
