For starters, check out this thread about Route 66
The Grand Canyon Hostel in Flagstaff rocks! I loved that place - one of the nicest hostels I've ever been to. In fact, the staff may still have a mix CD or two of mine at the front desk.
Keep an eye out for people posting their Grand Canyon tickets on the bulletin board there. The national park receipts are good for a week, I believe, so people just buy 'em and pass 'em on to the next traveler who happens upon it while it's valid.
I dunno if you've done Vegas before, but I'd personally advise against staying at the Stratosphere. It's waaaaaaaaay off the strip and away from the other attractions, and the neighborhood it's in has earned it the name of "Stratosfear."
If you have the time to detour from Santa Fe on the way to Arizona, I *very* highly recommend checking out Monument Valley, UT, near the four corners. One of the most beautiful places in the world, IMHO.