I too am from Arizona. There are literally hundreds of trails throughout the state. Check out http://www.az-fattire.com/home.shtml
for some ideas throughout the state. It also has links to the mountain bike racing schedule if you're interested in that.
As far as Flagstaff/Sedona goes there are numerous trails throughout both and the cool weather that is offered in both places is a major draw for the riders in the lower elevations. If you come to Flagstaff there are a number of bike shops that have trail information and lead group rides. I am not sure about Sedona, but I am sure they have the same.
I might also add that there is little to no road riding in Flagstaff and even less in Sedona. If you want to do road riding then stay in the Phoenix area or head down to Tucson... that's a roadies dream.
Hope this helps.
Last edited by Ba-Dg-Er; 04-17-02 at 11:59 PM.