The wife and I have traveled to Tucson, AZ several times while visiting family in Arizona.
The first place you go is the Pima Air Museum which has a large, outdoor static display of one version of each aircraft that has gone to the grave yard. There are several enclosed buildings and hangars as well with many restored aircraft.
From the museum you get your tickets and catch an enclosed, air condition bus which tours the Davis Monthan Air Base. You're not allowed to leave the bus once on base. Most of the unique aircraft has display cards, and there is a guide on board the bus as well to narrate the process. I picked up an excellent reference book back at the museum that outlines what is done to the aircraft such as preservation, cannibalizing or recycling.

--WH