Hiya
I've just got back last week from doing an entire circuit around the States for hour building and i'd recommend the following websites:
skyvector.com for a quick nav plog
aopa.org (sign up for a free trial) to print out the runway charts and taxiway diagrams. These are invaluable at the larger airports to save you having ATC screaming on the radio. (the iphone and blackberry have apps for this to download)
airnav.com to find the cheapest fuel (we were averaging about 4.20 usd a gallon)
and just to brighten your day.... fbo-hotties.com ! ;-)
Try to get as much planning organised the night before so you're ready to get going as soon as you can the next day. Ask the FBO's if they have crew cars or courtesy cars for free - most will ! And also find out if they are affiliated to any local hotels. We found that we would get about anywhere from 30% - 50% discount on a room rate.
Flying up the West coast was an amazing experience, only just beaten by Niagara Falls and Statue of Liberty & into JFK.
Again, remember density altitude. I always thought it was a mysterious and wonderful experience that only happened to old ATPL tutors...until I took off from Castle Merced AFB in 44 degrees...we were only managing a 50fpm climb!
Call 1-800-wx-brief before you deaprt to check for NOTAMs and a more intuitive info on the weather.
If your phone has wifi then you'll be able to logon to the FBO networks as they all give free access and you'll find that the planning rooms can get busy.
Finding FBO's that sell charts is actually harder than you would think and will again require calling multiple airfields on your route.
Re places to go - def land on the Grand Canyon - the approach and departure over a 4000ft drop will test your nerves!! Then it's a short hop to Las Vegas.
I missed out on the VFR corridor around LA but the route it takes is amazing, and is something I'll be back to do one day.
Flying around the Rockies was an experience that you'll be unlikely to forget and the only advice worth giving is to talk to the locals. They know the best routes to take and what time of day also. In fact, best to do this for every route - we had planned to flyover Camp David when President Obama was residing there and only found out because of the FBO owner!! Apparently, the Americans don't want us flying over at a 1000ft....
Try Burbank in LA and grab the black cadillac from Atlantic FBO then cruise into Hollywood and see Rodeo Drive!
have fun!