I just posted this info on another's person post, but it applies here so I'll cross-post it!
My opinion would be to take the 10 from Anahiem to Phx (you can stop to see the Joshua Tree National Park on the way), and then drive up the 17 to Sedona. Sedona is LOVELY, it is where we went on our honeymoon. Its definitely worth a stop by for lunch and some window shopping, if not staying over night. Tlaquepaque is a very fun little outdoor art/shopping area...great places to eat, lots to see, souvenirs, beautiful fine art, pretty buildings, etc. Or just walking up the boardwalk on downtown Main St. is more western-y, quaint shops with restaurants, etc. We took a Pink Jeep Tour to see the Indian Ruins and it was so fun and interesting. You get to see all the great scenery on the way. There are parks for picnicking, bike rentals, etc. Very romantic place. Our fav hotel is The Sedona Rouge...new, modern hotel, very chic and romantic. However, it is located in town, not out in the woods. There are some awesome cabins out in the woods if that's more your style.
From Sedona take the scenic Oak Creek Canyon Highway up to Flagstaff. It is the most beautiful drive in AZ. In Sept/Oct it will be gorgeous. Tons of Oak trees and winding streams the whole way up. Its really beautiful. From there you can go straight up to the Grand Canyon. I've always wanted to stay in one of the cabins there!
Also, along the way is Montezuma's Castle and Meteor Crater (if you're interested in those kind of things). You can also go the Observatory in Flagstaff, which is pretty neat, especially if you're into space stuff.