End of Oct brings some pretty nippy temps to the desert southwest.. Day riding is all but required unless you have some pretty warm gear.. (I discourage night rides in the mountains of the southwest at night anyway due to "critters" ranging from Elk to some reptiles that are still not hibernating yet).. Still some good riding time left but snow is not far away for the Grand Canyon.. (not to mention it gets wicked cold there at night)
Can not give you any recent camp ground advice but the KOA's are everywhere and most of the national parks have camping (a lot of empty stuff this time of year usually)
I would say "get a move on" if you are doing this in 2008...
Routes? too many to list but I would put salt river canyon on the agenda as well as most of northern AZ and my favorite... "Monument Valley" is about as humbling as the Grand Canyon.. It is an epic ride (and a lot of miles)
lots of boring stuff getting there is all...