http://phoenix.about.com/od/sportshi...-Trail-Map.htm
From Avondale, you can take Baseline East to Central Avenue and then take Central south to South MT Park. It is primarily a Mountain Bike Mecca. BUT, you can also just stay on the roads and climb to the towers or look out cabins. Its pretty cool. A lot of roadies make the trip.
This hook up will give you plenty of options as well. I grew up at the base of South Mountains. Used to ride my Schwinn varsity up there. The downhill was really exciting with those cheap brakes.
http://www.bikely.com/listpaths/coun.../124/city/7042
Good riding and Happy Thanksgiving. I was going to ride, but Golf has won out.